Gift of Growth Sale-mobile

HomeBlogBusiness intelligence and VisualizationPower BI vs Tableau: Which Data Visualization Tool is Right for You?

Power BI vs Tableau: Which Data Visualization Tool is Right for You?

Published
02nd May, 2024
Views
view count loader
Read it in
19 Mins
In this article
    Power BI vs Tableau: Which Data Visualization Tool is Right for You?

    Step into the realm of data visualization with a comprehensive exploration of Power BI and Tableau. In a world where data is important, deciding between power bi vs tableau can change your path in analyzing things. As we explore the pasts and ways that Power BI and Tableau work, it'll help us understand what makes these tools special. If you are an expert in working with data or a beginner excited to use visualization, this blog will help you understand the differences between power bi and tableau.

    We are talking about tableau vs power bi market share using features, interfaces and performance. We want to assist you in choosing the best option for what you need. Come with us on this journey to find out which tool, Power BI or Tableau, matches up well with your goal of showing data in pictures. Are you ready to unlock my data potential and master advanced analytics! Enroll in the tableau certification course today to gain the expertise you need.. 

    Power BI vs Tableau: Comparison Table

    PropertiesTableauPower BI
    CostTableau is more costly; the pro edition costs over $35 per month for each user.Compared to Tableau, Power BI is less expensive.
    Performance
    Tableau offers a wide range of tools for data visualization and is appropriate for fast handling large amounts of data.Utilizing Power BI is simple. While the data volume is small, it operates more quickly and effectively but becomes sluggish when processing mass data.
    User Interface
    Tableau has an intelligent interface and allows you to create and edit dashboards according to your requirements.Power BI has a user-friendly user interface and is compatible with other Microsoft applications.
    Data Sources
    Tableau Software can access many data sources and servers.The thing about Power BI is that it supports different data sources.
    The ease of Using
    Tableau provides some crucial advantages for detailed data exploration and visualization.Power BI has the advantage of ease of use because it is based on a user interface rooted in Microsoft Office 365.
    Programming Support
    Compared to Power BI, Tableau integrates much better with R.Power BI supports Data Analysis Expression and the M language for data manipulation and modeling.
    Data Visualization
    Tableau allows its users to customize dashboards specifically for devices.Power BI provides easy-to-use drag-and-drop functionality.
    Machine Learning
    Tableau supports Python machine learning features.Power BI takes advantage of Microsoft's business analytics.

    The business intelligence market has multiplied in recent years and is anticipated to do so going forward. You should be data-driven if you want to pursue your career in Business Intelligence, Analytics, or Data Science. KnowledgeHut offers Business Intelligence and Visualization classes that will help you hone your skills in Business Intelligence. 

    Tableau vs Power BI: Key Differences

    What is Tableau?

    Tableau is a visual analytics platform changing how we use data to solve problems – empowering people and organizations to get the most out of their data. It is an excellent data visualization and business intelligence tool for reporting and analyzing vast volumes of data. It helps users create charts, graphs, maps, dashboards, and stories to visualize and analyze data to help them make business decisions. 

    10 important properties of Tableau:

    PropertiesDescription
    Informative Dashboards
    combine images, visual objects, text, and other components to present a comprehensive view of your data.
    Supports numerous data sources
    It connects to and fetches data from a variety of data sources using Tableau and supports a wide range of data sources, including local files, spreadsheets, relational and non-relational databases, data warehouses, big data, and on-cloud data.
    Connectivity with Live and In-Memory Data
    Allows the user to freely combine data from several types of data sources.
    Provides Great Security
    Data connections and user access feature a fail-safe security system based on authentication and authorization mechanisms.
    Easy Collaboration & Sharing
    Easy ways for users to communicate with one another and exchange data in real-time in the form of visualizations, sheets, dashboards, and so on
    Provides a Mobile Version
    It offers a mobile version of the app and Dashboards and reports may be created in a mobile-friendly format.
    Advanced Visualization Capabilities
    It allows you to create visualizations as simple as a bar chart or a pie chart, as well as more complex ones like a histogram, Gantt chart, Bullet chart, Motion chart, Treemap, Boxplot, and many others.
    Availability of Maps
    It comes with a lot of pre-installed map data, including cities, postal codes, administrative borders, and so on.
    The Ask Data Tool
    It simplifies data manipulation by allowing us to conduct basic Google searches.
    Trend Lines & Predictive Analysis
    The use of time series and forecasting by Tableau is another really useful feature. Creating trend lines and forecasts is straightforward with Tableau’s powerful backend and dynamic front end.

    what is tableau
    Tableau Interface 

    What is a Power BI?

    Power BI is business analytics software offered by Microsoft, which enables users to share insights and display their data. It is a cloud-based suite of business intelligence and data visualization tools that started as an Excel add-in. Its mission is to "create a data-driven culture with business intelligence for all." Power BI uses Microsoft systems like Excel, Azure, and SQL, so it's easy to pick up for those already using Microsoft products. The platform has more than 100 connectors and has drag-and-drop functionality, making it easy to use.

    Power BI Dashboard
    Power BI dashboard 

    Power BI vs Tableau: Detailed Comparision

    When I move through the complex area of data visualization, picking between tableau and power bi makes a big choice. Let's look closely at both options to see which one fits my thinking goals better. In this section we are discussing about the  tableau and power bi difference and Help for Users in Power BI and Tableau Software

    Customer Support in Power BI and Tableau

    Is power bi and tableau the same? This clear table looks closely at the customer help features in Power BI and Tableau. It helps users choose what they like or need from both tools, so they can make good decisions about which one is best for them.

    Customer Support FeaturePower BITableau
    Community SupportPower BI boasts a robust online community, with active forums and extensive resources. Users can engage in discussions, seek advice, and share insights.Tableau's community support is dynamic, fostering a vibrant user forum environment. It provides a platform for users to participate in discussions, troubleshoot issues, and exchange valuable knowledge.
    Official SupportPower BI offers robust official support channels, including a comprehensive knowledge base, official documentation, and responsive customer support. Users can access a range of resources for issue resolution and guidance.Tableau provides strong official support, ensuring users have access to various help and contact options. This includes official documentation, a dedicated support portal, and responsive customer service channels to address queries and concerns.
    Training ResourcesMicrosoft provides extensive training resources for Power BI users. This includes online courses, tutorials, and documentation to help users build their skills and proficiency with the tool.Tableau offers a wealth of training materials, including online courses, webinars, and documentation. The training resources cover a variety of skill levels, enabling users to enhance their proficiency in Tableau's features and functionalities.
    DocumentationPower BI is well-documented, providing users with detailed online guides, tutorials, and documentation. The resources cover a wide range of topics, ensuring users have access to comprehensive information for effective usage.Tableau's documentation is comprehensive, offering detailed guides and resources for users and administrators. The documentation serves as a valuable reference for understanding Tableau's features, troubleshooting, and optimizing performance.
    User ForumsPower BI's user forums are vibrant and active, providing a platform for users to discuss topics, share experiences, and seek solutions to challenges. Community engagement contributes to a collaborative learning environment.Tableau's user forums are lively spaces for discussions and knowledge sharing. Users can participate in forums to connect with peers, gain insights, and find solutions to queries, fostering a sense of community among Tableau users.

    Power BI and Tableau: Performance

    When doing comparison power BI and tableau performance, how fast and well they handle data becomes the main focus. Let's look carefully at their abilities, assessing how fast they can work, whether or not they expand well and all around performance.

    Performance AspectPower BITableau
    Speed of Data RenderingIn my experience, Power BI exhibits commendable speed in rendering visualizations, particularly with smaller datasets.Tableau, on the other hand, stands out for its exceptional speed, ensuring swift rendering even when dealing with large and complex datasets.
    ScalabilityPower BI provides scalability that suits small to mid-sized datasets and organizations, making it adaptable for various scenarios.Tableau excels in scalability, showcasing its prowess in handling large datasets with ease and delivering optimal performance as data volumes expand.
    Data Refresh RatesI appreciate Power BI's flexibility in offering customizable data refresh rates, allowing me to manage the frequency based on my specific analytical needs.Tableau also provides flexible data refresh options, enabling me to schedule and manage data updates according to my preferences.
    Real-time Data ProcessingPower BI supports real-time data processing, a feature I find valuable for working with live data and obtaining immediate insights.Similarly, Tableau supports real-time data processing, empowering me to engage with live data for dynamic and up-to-the-minute analyses.
    Resource UtilizationPower BI impressively utilizes system resources, delivering a smooth experience even on standard hardware configurations.Tableau, being resource-intensive, shines with powerful hardware configurations, maximizing performance, especially with visually intricate and resource-demanding analyses.

    Both power BI and tableau are good at doing different things when it comes to performance. They each have their own strong points. Power BI has a way that works for many different situations. On the other hand, Tableau is really fast and can handle large amounts of data well especially when dealing with big stuff.

    Power BI and Tableau: Certifications

    Starting my trip to learn Power BI or Tableau, I need to think about getting certificates that show how good they are. In the realm of Power BI, the Microsoft Certified: The Data Analyst Associate certification is very important. This test not only shows that I know Power BI Desktop, but it also proves my ability to use Power Query and create visual data. Furthermore, complementing this is the Microsoft Certified: Certification for Power Platform Basics, this gives me a good start to understand everything in the wider world of Power Platform.

    For Tableau, a good route of tests helps me show that I'm really skilled. I can show my skills in basic ideas of Tableau Desktop by starting with the Tableau Desktop Specialist. By getting the Tableau Desktop Certified Associate and later becoming a Tableau Desktop Certified Professional, I can prove my skills in finding data, doing tests on it. Finally using tools like visuals to make subtle changes that matter much with help from powerful software calledTableau.

    No matter if my job is in data checking or showing information visually, these certificates help show that I'm good at it. They not only tell bosses how good I am but also help me learn the abilities of each tool. Deciding between power bi vs tableau certifications fits with what my group needs and likes in the changing world of data analysis and business knowledge.

    Power BI and Tableau: Security

    Making sure my data is safe is very important in my journey with analytics. Let's look closely at the security parts of power bi and tableau. We will check things like who can use them, keeping data safe from prying eyes, and rules for how they should be managed.

    Security Aspect
    Power BI
    Tableau
    User Authentication
    Power BI seamlessly integrates with Azure AD, supporting single sign-on and multi-factor authentication for my peace of mind.
    Tableau offers flexible authentication methods, including AD, SAML, and OpenID Connect, ensuring a robust verification process for me.
    Data Encryption
    Power BI ensures secure communication by utilizing SSL/TLS encryption during data transmission, keeping my information safe.
    Tableau implements SSL/TLS, guaranteeing secure data transmission and storage, providing a sense of confidence in data protection.
    Role-Based Access Control
    Power BI empowers administrators like me with role-based access control, allowing us to define user roles and permissions securely.
    Tableau's role-based access control enables granular permissions, providing me with enhanced control over data security.
    Row-Level Security
    With row-level security, Power BI lets me, as an administrator, control data access at the row level based on user roles and filters.
    Tableau incorporates row-level security, allowing me to define data access based on user attributes and filters for robust data protection.
    Data Masking
    Power BI offers dynamic data masking based on user roles for sensitive data, ensuring that only authorized users view complete information.
    Tableau provides data masking, allowing administrators like me to control the visibility of sensitive data based on user roles and permissions.
    Audit and Compliance Logging
    Power BI includes audit and compliance logging, enabling me to monitor user activities and changes for security monitoring purposes.
    Tableau offers robust audit logging, allowing me to track user interactions and ensure adherence to security policies within the platform.
    Integration with Security Tools
    Power BI seamlessly integrates with Microsoft Defender for Endpoint and Azure Sentinel for advanced threat detection and response, enhancing overall security.
    Tableau provides integration with SIEM systems, offering enhanced threat detection and response capabilities for a more secure environment.
    Data Governance
    Power BI incorporates data governance features, allowing administrators like me to define and enforce data quality and compliance standards.
    Tableau offers comprehensive data governance capabilities, enabling administrators to establish data quality, integrity, and compliance standards effectively.

    When looking at how safe power bi and tableau are for keeping data, both tools promise good steps to protect your information. Each one has strong points but also things you need to think about carefully before making a decision.

    Features of Power BI vs Tableau

    Power BI Features 

    1. Customizable dashboards: A dashboard typically comprises several widgets and visualizations in Power BI. A widget is a single chart or other graphic produced through data analysis. Combining one or more widgets, you can generate Power BI reports. 

    2. Power BI Service: It enables users to share reports or dashboards on the cloud and local servers with other users. With Power BI, we can add more connectors, create workspaces where our partners can work with us on reports and dashboards, and enable AI features like Power Query for a seamless data flow, making it easier for users to work on Power. BI projects. 

    3. Data Analysis Expressions (DAX) functions: Data analysis expressions in Power BI are a set of predefined codes used to perform operations on data. There are currently more than 200 DAX functions in the Power BI function library that can be used to streamline business data analysis. 

    4. Natural language question box: Power Q&A enables users to search data, transform it and create visuals by asking questions in natural language. Users need to double-click the dashboard and type in the variable they want to add, selecting the desired chart or chart name, and Power Q&A will create the visual. 

    Tableau Features 

    1. Tableau dashboards: Tableau dashboards may show the data as stories and include several filters, layouts, and styles. They allow users to copy them or their pieces from one report to another and apply a custom filter. 

    2. Data sources in Tableau: Tableau has several data sourcing methods for obtaining data from various sources, including relational and non-relational databases, data warehouses, on-premises, and on-cloud data, big data, and more. We may construct a secure link with data sources to generate visually interactive reports and obtain a combined data view. 

    3. Data connectors: Numerous data connections are supported by Tableau, including those for Dropbox, SQL Server, Salesforce, Google Sheets, Presto, Hadoop, Amazon Athena, and Cloudera. 

    4. Advanced visualizations: Users can customize reports by adding different Tableau graphics based on their needs. Tableau offers a wide variety of visualizations, from simple pie or bar charts to more complex treemaps, boxplots, histograms, motion charts, Gantt charts, bullet charts, donut charts, etc. 

    User Interface of Power BI and Tableau

    Power BI has a user-friendly user interface and is compatible with other Microsoft applications.  For gaining expertise in Power BI and understanding the benefits of using Power BI, a Power BI training will help to learn Power BI Interface. It's easy to use and increases your productivity. Report View, Data View, and Model View are the three views offered by Power BI Desktop that you can choose from on the left side of the canvas. 

    Tableau has an intelligent interface that allows you to create and edit dashboards according to your requirements. It has a nice desktop that encourages you to experiment with data and get brilliant results. The workspace area has various tabs and shelves, a toolbar, a sidebar, a data source page, a status bar, and sheet tabs. 

    Data Sources in Power BI and Tableau

    The thing about Power BI is that it supports different data sources. Still, compared to Tableau, it has limited access to other databases and servers. Some examples are Microsoft Excel, Text/CSV, folders, MS SQL Server, Access DB, Oracle Database, IBM DB2, MySQL database, PostgreSQL database and etc. 

    Tableau Software can access many data sources and servers such as Excel, text files, PDF, JSON, statistics files, Amazon Redshift, Cloudera Hadoop, Google Analytics, dropbox, google sheets, google drive, and more. 

    Ease of Using Power BI and Tableau

    Power BI has the advantage of ease of use because it is based on a user interface rooted in Microsoft Office 365 that most end users are already familiar with. 

    Tableau provides some crucial advantages for detailed data exploration and visualization. Tableau also incorporates natural language capabilities into its software. This helps in finding solutions to complex problems by better understanding the data. 

    The business intelligence market has multiplied in recent years and is anticipated to do so going forward. You should be data-driven if you want to pursue your career in Business Intelligence, Analytics, or Data Science. KnowledgeHut Business Intelligence and Visualization classes will help you hone your skills in Business Intelligence. 

    How is Tableau different from Power BI?

    Power BI leverages existing Microsoft systems like Azure, SQL, and Excel to create data visualizations that don't break the bank. This is an excellent option for those already working with Microsoft products such as Azure and Excel. It's also a perfect low-cost option for small-medium businesses and startups that need data visualization but don't have a lot of extra capital. 

    Tableau specializes in creating beautiful visualizations, but its advertising is aimed at corporate environments with data engineers and bigger budgets. There is a public (free) version of the tool, but with limited options. The more you pay, the more you can access Tableau, including benchmarking data from third parties. The software also has a non-profit utility and an academic version. 

    Programming Support for Power BI and Tableau

    Power BI supports Data Analysis Expression and the M language for data manipulation and modeling. It can also connect to the R programming language using Microsoft's Revolution Analysis but is only available to enterprise-level users. 

    Compared to Power BI, Tableau integrates much better with R. The Tableau Software Development Kit can be implemented using four programming languages – C, C++, Java, and Python. Connecting to these programming languages can create even more powerful visualizations. 

    Data Visualization in Power BI and Tableau 

    Power BI provides easy-to-use drag-and-drop functionality. It provides features that make data visually appealing. Power BI offers a wide range of detailed and attractive visualizations to create reports and dashboards. In Power BI, you can query your data to get meaningful information. 

    Tableau allows its users to customize dashboards specifically for devices. It provides interactive visuals that support ongoing insights. It can turn queries into visualizations and let you ask questions, spot trends, and identify opportunities. You don't need prior knowledge to work with Tableau as it provides built-in spreadsheet calculations for creating reports and dashboards 

    Machine Learning in Power BI and Tableau

    Power BI takes advantage of Microsoft's business analytics, which includes platforms such as Azure Machine Learning, SQL Server-based Analysis Services, real-time data streaming, and many Azure offerings. It helps to understand the data and analyze the trends and patterns in the data.

    Tableau supports Python machine learning features. This allows us to perform machine learning operations on datasets and forecast data.

    Advantages and Disadvantages of Power BI  and Tableau

    Here is a list of the benefits of these Business Intelligence tools before concluding this Tableau vs. Power BI debate: 

    Advantages of Power BI

    1. Price: Power BI provides all features and services for $10 per user per month. With Power BI Pro, the user can access the full range of Power BI components and Microsoft services such as Cortana to trigger voice queries. 
    2. MSFT Integration: Power BI can be easily integrated with Azure/O365 and anything else created by Microsoft, which is a huge advantage for users as all operations run smoothly on Microsoft. 
    3. Ease of use: For beginners, Power BI provides an intuitive learning curve, and the interface resembles that of MS Excel, making it easy to navigate. In Power BI, we can take advantage of the DAX query language and run queries on datasets in natural language. 
    4. ETL/Discovery suite: Compared to Tableau, Power BI has a robust set of tools for implementing ETL functions. Data preparation accounts for more than 90% of all reporting requirements, and Power BI can directly create these data marts for reporting without the use of third-party software. 

    Advantages of Tableau

    1. High performance: Tableau provides the user with high data visualization and transformation. It also works faster on large data sets with greater efficiency. This powerful feature gives Tableau an edge over other Data Analytics toolkits. 
    2. Connect to multiple data sources: Tableau can connect to various data sources such as Hadoop, DB Technologies, SAP, and Google BigQuery. This improves the quality of data analysis and allows the user to create informative reports. Reports with such a connection provide accurate information about the situation and help the user make better decisions. Tableau uses languages like Python and R for complex spreadsheet calculations and avoids performance degradation. 
    3. Thriving Community and Forum: Through collaboration and sharing, Tableau fans provide valuable insights and community resources to help newcomers increase their data analysis and reporting knowledge. By sharing their experiences with the software, forum visitors help each user solve their problems. 
    4. Mobile-friendly: With mobile apps, Tableau allows users to have all the statistics at their fingertips. Tableau apps are available for Android and iOS devices and support all Tableau Desktop features. 

    Disadvantages of Power BI and Tableau

    We have discussed the best parts of using these tools; now, let's focus a little on the cons or disadvantages of these tools. 

    Disadvantages of Power BI

    1. Relationships between tables: Power BI is prone to problems when processing data that has complex relationships with tables. In many cases, you must carefully create data models with unique fields just to join tables. 
    2. User Interface: Power BI has a cluttered interface with many icon options that prevent reports and dashboards from being displayed. In addition, the label in Power BI has limited functionality. 
    3. iOS Compatibility: Power BI does not have a compatible option for Mac desktop users. Power BI cannot be installed directly on iOS; a virtual machine must be installed to run Power BI Desktop. 
    4. Limited Excel integration: Excel integration is a significant benefit of Power BI, but only data up to 150,000 rows can be downloaded, which can be very limiting sometimes. 

    Power BI is an excellent tool for analyzing and visualizing data; the pros far outweigh the cons. 

    Disadvantages of Tableau

    1. High cost: Tableau is not too expensive compared to BI giants like IBM and Oracle. However, the license is more costly when placed in the same bucket with other competitors such as Power BI. This won't be a problem for large organizations, but it will be a significant disadvantage for small and medium-sized companies where money is central to all decisions. 
    2. Steep Learning Curve: In light of the learning curve, Tableau is quite steep as the user needs proper data analysis training and decent R and Python programming skills. Also, data extraction, transformation, data modeling, and visualization are entirely manual, which means we can face data incompetence when connecting our data sources to Tableau. On the other hand, if we know the interface well in Power BI, we just write our queries in our language using Power Query or drag and drop our data columns into the visuals. 
    3. Time and resource-intensive staff training: Tableau does not require technical knowledge to perform basic operations. However, like Power BI maintains user-friendliness for complex processes, Tableau does not. Tableau users must undergo comprehensive staff training to perform such functions. 
    4. Complex integration with Microsoft BI solutions: Microsoft has many BI solutions and cloud services that multiple organizations use. While Power BI can easily integrate with them and provides better efficiency with features like Power Q&A and Power BI Service, on Tableau, integration with products like Dynamics 365, Microsoft Flow, and Office 365 is a bit exhausting because of the only one-per process.

    Power BI vs Tableau: Which is Better?

    So which is better, Power BI or Tableau? Your choice depends on how you need to use these tools in your business. Power BI is the winner of Tableau versus Power BI due to its ease of use, similarity to Excel, and affordable pricing making it an excellent choice for many businesses. 

    Tableau still has unique benefits that many companies and analysts will appreciate. It's better for larger volumes of data and offers beautiful data visualizations and more excellent customization options than Power BI. 

    Boost your career now with best business management certifications. Acquire the expertise to lead, strategize, and thrive in today's cutthroat environment.

    Conclusion

    In the end, looking at power bi vs tableau differences shows that one platform has better customer support while the other is faster. They both have training courses but also safety measures for protecting your data in their own ways. I've seen that Power BI shows good fast working and wise use of resources, but Tableau is very quick and can handle more work. Both systems offer strong help for customers, lots of learning tools and different ways to prove my skills. Both tools have security features like user verification and data protection, which make me sure about keeping information safe. In the end, it's up to me and what my project needs. Power BI and Tableau are both good choices for seeing data in an interesting way. But each one has its own special things that can help with mining information from numbers or other stuff we look at on computers.

    Frequently Asked Questions (FAQs)

    1. Is Power BI or Tableau easier to learn?

    For new users and non-data analysts, Power BI is simpler to use. Tableau is recognized to have a more demanding learning curve; it is more prevalent among seasoned data analysts. 

    2. What are the advantages of Power BI over Tableau?

    Power BI's advantages over Tableau are: 

    1. Its familiar Office 365 interface is quicker and easier to grasp, but Tableau's Visual Query Language is more user-friendly than Power BI's DAX. 
    2. Small teams can afford Power BI more easily. For bigger enterprises, Tableau might be a better choice. 
    3. Due to its close connection with other Microsoft platforms like Azure Machine Learning, Power BI has more sophisticated machine learning capabilities. 

    3. What pays more, Tableau or Power BI?

    Depending on your experience and skill level, salaries for Tableau developer positions might range from 4L to 9L or more. Depending on your experience and qualifications, the pay for Power BI developer employment might vary from 3L to 10L or even more. Tableau vs. Power BI salary comparison shows that the salary of Power BI and Tableau falls in the same range and varies per experience and skill. 

    Profile

    Utpal Kar

    Blog Author

    Utpal Kar, a seasoned Corporate Trainer, excels in conducting training programs encompassing Advanced Excel, Power BI, Python, SQL Server, and Unix/Linux technologies. Notably, he holds a Python Certification from LinkedIn, showcasing his proficiency in the domain. Currently serving as a Corporate Trainer at Innovative Technology Solutions, Utpal specializes in Python, VBA Macro, Advance Excel, Power BI, and PostgreSQL, along with a breadth of other languages like .Net and Java. Prior to this role, he made significant contributions at NIIT Ltd., providing technical support and solutions to Franchisee Centres. With over 4 years at Innovative Technology Solutions, Utpal remains dedicated to enhancing skill sets and driving performance for professionals across various industries.

    Share This Article
    Ready to Master the Skills that Drive Your Career?

    Avail your free 1:1 mentorship session.

    Select
    Your Message (Optional)

    Upcoming BI & Visualization Batches & Dates

    NameDateFeeKnow more
    Course advisor icon
    Offer
    Whatsapp/Chat icon