emWeb

SEGGER emWeb is a compact, production-grade web server for embedded systems that enables browser-based graphical user interfaces, configuration panels, and monitoring dashboards accessible from any PC, Mac, smartphone, or tablet. With a footprint of approximately 8 KB ROM and 2.5 KB RAM in release builds, emWeb fits on resource-constrained microcontrollers while delivering modern web capabilities including WebSockets for bidirectional real-time communication, REST API endpoints, AJAX for asynchronous updates, and Server-Sent Events (SSE) for efficient server-push notifications.

Dynamic Content and Web Standards

emWeb supports multiple techniques for generating dynamic content, giving developers the right tool for each use case:

This range of dynamic content methods means emWeb can serve everything from simple status pages to rich single-page applications that rival desktop software in responsiveness.

Core Capabilities

• Small, predictable footprint: approximately 8 KB ROM and 2.5 KB RAM in release builds, leaving headroom for application logic on the same microcontroller
• Multiple dynamic content models: CGI, virtual files, AJAX polling, SSE server-push, and full-duplex WebSockets, so a single library covers status pages through interactive dashboards
• Form and REST handling: POST/GET processing and REST endpoints for configuration input and programmatic access from external tools
• Transport flexibility: runs over Ethernet, WiFi, or USB, so the same web server code serves a browser interface regardless of which physical connection a product uses
• Thread-safe operation: runs as a separate thread in any multitasking environment, isolating web request handling from time-critical application code

Connectivity and Integration

emWeb runs as a separate thread in any multitasking environment and works with any RFC-compliant TCP/IP stack, with optimised integration for SEGGER emNet. Connectivity extends beyond Ethernet, emWeb supports WiFi and USB connections (via SEGGER’s IP-over-USB and emUSB-Web technology), enabling browser-based device interfaces even for products without an Ethernet jack. Common deployment scenarios include router configuration pages, printer management interfaces, industrial HMI panels, and IoT device dashboards. Royalty-free, one-time-payment licensing with no subscription fees keeps production economics straightforward.

SEGGER Ecosystem Integration

Because emWeb is optimised for emNet, teams already running emNet for general TCP/IP connectivity gain a browser-based configuration interface without introducing a second network stack. For deployments that must protect the configuration interface from unauthorized access, emWeb combines with emSSL to serve the same dashboards and REST endpoints over HTTPS, and with emSecure where the web interface is used to trigger a signed firmware update. This shared-vendor approach means the web server, network stack, and security layer are tested together rather than integrated as separate third-party components.