Skip to main content
  • Products
  • Evaluate our Software
  • Downloads
  • Free Utilities
  • Purchase
  • Silicon Vendors
  • Support
  • About Us
  • Blog
  • Forum
  • Search
  • Jobs
  • Newsletter
  • Blog
  • Contact
  • Shop
  • emWeb—Web Server

    emWeb

    Web server to control targets with graphical interfaces

    Contact us
    Downloads
    Documentation
    SEGGER emWeb
    1. 1.Key features
      1. 1.1.User interface via Ethernet, WiFi, and USB
      2. 1.2.Support for modern web standards
      3. 1.3.Platform-independent
    2. 2.Use cases
      1. 2.1.IoT and networked devices
      2. 2.2.Broad integration of USB-connected devices
    3. 3.How emWeb works
    4. 4.Requirements
    5. 5.Dynamic Content
      1. 5.1.Dynamic page examples
    6. 6.emWeb Live Statistic Sample
    7. 7.Licensing

    Overview

    emWeb enables seamless integration of graphical user interfaces (GUIs) into embedded systems and applications. With support for HTML and modern web technologies, emWeb is the ideal tool for developers to create user-friendly interfaces that are platform-independent and accessible via any web-enabled device.


    Key features

    A circular teal background features three white icons: an Ethernet port, a wireless signal, and a USB connector. These symbols represent different types of internet and data connectivity options, highlighting the importance of networking technology.

    User interface via Ethernet, WiFi, and USB

    emWeb supports providing a web-based GUI (web-based graphical user interface) over multiple communication interfaces, including Ethernet, WiFi, and USB. This flexibility allows the user interface to be accessible from a variety of devices, regardless of the type of connection, ensuring seamless control and configuration across different platforms and environments.

    A circular icon featuring a simplified globe design in white, set against a teal background. The globe is represented by curved lines and grid patterns, symbolizing global connectivity and geography.

    Support for modern web standards

    emWeb supports modern web standards such as WebSockets, REST, AJAX, and Server-Sent Events (SSE). These technologies enable real-time, bidirectional communication, smooth integration with external systems, and dynamic, asynchronous updates to the user interface, making emWeb ideal for interactive and performance-critical embedded applications.

    Icon representing various digital devices: a desktop computer, a laptop, and a smartphone, arranged around a central circle. The background is a teal color, emphasizing connectivity and digital interaction among these devices.

    Platform-independent

    emWeb offers complete platform independence, meaning both the host system and the end-user viewing device can operate on any platform. Whether the host is running a specific embedded system or a general-purpose OS, and whether the user is accessing the UI from a PC, Mac, smartphone, or tablet, emWeb ensures broad compatibility across diverse hardware and software environments.


    Use cases

    A dark background filled with cascading vertical lines of binary code (0s and 1s) creates a digital, futuristic atmosphere. The pattern gives a sense of depth, resembling a virtual tunnel or data stream, enhancing themes of technology and information.

    IoT and networked devices

    emWeb is highly effective for managing and configuring IoT devices such as routers, switches, printers, and oscilloscopes, as well as a broader range of networked devices. With its browser-based UI, emWeb enables remote configuration and monitoring, regardless of the operating system. This makes emWeb a versatile tool for managing diverse devices across different environments with minimal development effort.

    A dark background filled with cascading vertical lines of binary code (0s and 1s) creates a digital, futuristic atmosphere. The pattern gives a sense of depth, resembling a virtual tunnel or data stream, enhancing themes of technology and information.

    Broad integration of USB-connected devices

    Using SEGGER’s IP-over-USB technology, emWeb enables a browser-based UI for virtually any device with a USB connector. From portable devices like wireless headphones and fitness trackers to industrial systems, emWeb supports a wide variety of applications, allowing users to configure, monitor, and manage devices via a web interface.


    How emWeb works

    emWeb operates as a lightweight web server within the target device or application. It processes HTTP requests and delivers dynamic content using techniques like CGI for custom applications, virtual files for real-time data updates, and AJAX/SSE for interactive user interfaces. The server integrates smoothly with existing TCP/IP stacks and can even be used with USB devices via SEGGER's IP-over-USB technology. Using SEGGER's emUSB-Web technology, it is possible to use emWeb even without any TCP/IP stack.

    emWeb also supports several authentication mechanisms.

    Requirements

    TCP/IP stack: emWeb requires a TCP/IP stack. It is optimized for emNet, but any RFC-compliant TCP/IP stack can be used. The shipment includes a Win32 implementation sample which uses the standard Winsock API, as well as an implementation which uses the socket API of emNet.

    Multitasking: The web server needs to run as a separate thread. Therefore, a multitasking system is required to use the web server emWeb.

    Resource usage: The following table shows the approximate resource requirements for a typical web server configuration:

    DescriptionROMRAM
    emWebApproximately 8 KByteApproximately 2.5 KByte
    emNetApproximately 20 KByteApproximately 25 KByte
    embOSApproximately 4.4 KByteApproximately 3.4 KByte

    Values measured in release mode with size optimization for a single task web server


    Dynamic Content

    emWeb supports different techniques to create dynamic pages.

    TechniqueDescription
    CGIs

    The Common Gateway Interface (CGI) is a replace mechanism that is used in conjunction with a template page. A visitor counter in a page with static content would be one of the simplest use cases.

    The template page can be a simple HTML page with a placeholder for the counter value. Whenever the page is processed by emWeb, the placeholder will be exchanged for the output of a custom application code.

    Virtual filesVirtual files allow to deliver complete pages that are built when they are requested. Typical examples are XML files that represent the current state of an application and are therefore subject to change for almost every request.
    AJAX

    AJAX is an acronym for Asynchronous JavaScript and XML. Together with browser DOM (Document Object Model) support, it allows dynamic modification of a page without requiring to reload the complete page.

    To request data, with AJAX the browser needs to poll for data.

    SSE

    Unlike AJAX, Server-Sent Events (SSE) are an HTML5 technique that allows a server to send data to the browser, without the browser permanently polling for data and therefore reducing unnecessary data overhead.

    SSE works by the browser subscribing to the Web server and keeping the connection up for further data sent.

    Form handling

    emWeb includes robust support for form handling via both POST and GET methods, allowing for efficient data submission and retrieval from clients. The integrated API ensures that form data is processed in a simple and memory-efficient manner, making it ideal for applications that require user input or configuration settings.

    Dynamic page examples

    List of three TCP connections
    Live statistics of the TCP connection
    Exemplary graph showing stock prices in a red curve
    Live updated graph
    IP configuration, incl. IP address, Subnet Mask, Gateway
    Network configuration

    emWeb Live Statistic Sample

    The chart sample is part of the emWeb shipment. The sample can easily be modified to fit your needs.

    In the sample application, that is available for Windows and can be downloaded below, emWeb is listening on TCP port 8181. To access the web page after starting the executable, the web browser should be directed to: http://127.0.0.1:8181.

    Download emWeb Web server live statistics sample

    startscreen_emweb

    emWeb Web server live statistics sample


    Licensing

    A digital graphic promoting a sale with a bold "25% off 2nd seat*" message at the top, and a prominent "FREE Professional Tools" note at the bottom, indicating availability for non-commercial use. The background features a pattern of binary code.

    emWeb is available under various embedded software license models and delivered in source-code packages. Every license model includes a 6-month support-and-update agreement, and there is also an option to extend both support and updates for an additional 12 months. All licenses are one-time payments, royalty-free, and not subscription-based. To purchase a license, please contact us.

    * Applies only to a second license and any additional license(s) purchased for the same product under the Single Product License and Single Developer License.


    SEGGER's Friendly License

    emWeb is also available under SEGGER's Friendly License, which allows free-of-charge use for non-commercial, evaluation, and educational purposes. With this license, the product is fully functional and there are no technical limitations. To download the license, please visit https://www.segger.com/downloads/emweb/.

     

     Request a quotation      Detailed pricing information

    Get in touch with us

    Have questions or need assistance? Our Embedded Experts are here to help!

    Reach out to us for:

    • Licensing quotes
    • Technical inquiries
    • Project support

     

    Contact us

    • User manual
    • Online documentation
    • List of downloads
    • Update notification
    • Pricing
    • Support
    • Silicon vendor resources

    Headquarters

    SEGGER Microcontroller GmbH

    Ecolab-Allee 5
    40789 Monheim am Rhein, Germany
    info@segger.com
    Tel.: +49-2173-99312-0
    Fax: +49-2173-99312-28

    Locations

    USA: SEGGER Microcontroller Systems LLC

    Boston area
    101 Suffolk Lane
    Gardner, MA 01440, USA
    us-east@segger.com
    Tel.: +1-978-874-0299
    Fax: +1-978-874-0599

    Silicon Valley
    Milpitas, CA 95035, USA
    us-west@segger.com
    Tel.: +1-408-767-4068

    China: SEGGER Microcontroller China Co., Ltd.

    Room 218, Block A, Dahongqiaoguoji
    No. 133 Xiulian Road
    Minhang District, Shanghai 201199, China
    china@segger.com
    Tel.: +86-133-619-907-60

    ISO 9001 certified

    ISO 9001

    30+ years of experience

    First-class embedded software tools since 1992
    • Imprint
    • Disclaimer
    • Code of Conduct
    • Privacy Policy
    © 2025 SEGGER - All rights reserved.