Annotate any webpage with drawings, highlights, threaded comments, and arrows — then share one link. Anyone who opens it sees your annotations live, with real-time cursors and synced updates via WebSocket. Voice and video chat included via WebRTC. No account required. Open source. Auto-expires in 30 days.

Free, open-source web annotation tool. Draw, highlight, and pin threaded comments on any live webpage, then share one link for real-time collaboration (live cursors, voice/video). New since launch: an element inspector for AI-ready handoff, a measure tool, and an MCP server so agents like Claude Code can resolve your annotations as a work queue. No accounts, ever.

Hey PH 👋 — I'm Vadym, the solo dev behind MarkLayer. We first launched here back in March, thanks to everyone who checked us out then. Since that launch we've shipped a lot based on what people needed: → An element inspector that captures a stable CSS selector + AI-ready context for any element → An MCP server (marklayer-mcp) so AI coding agents like Claude Code can watch a share link and resolve annotations as a work queue → A measure tool for pixel-precise distances between elements → Still 100% free, fully open source (Apache-2.0), no accounts, ever The core idea hasn't changed: giving feedback on a live webpage shouldn't mean screenshot → paste into Figma → explain the context → 30-message thread. MarkLayer puts an annotation layer directly on top of any URL, and now that feedback can flow straight into your AI agent's task queue. Would love your feedback, what's missing for your workflow? AMA 🙏

MarkLayer

Draw & comment on any webpage — share one live link

Draw & comment on any webpage — share one live link

MarkLayer

Previous MarkLayer Launches

Previous MarkLayer Launches