# cnvs.app — Free, No-Signup Collaborative Whiteboard > **TL;DR.** cnvs.app is a free, no-signup, real-time collaborative whiteboard > in the browser. Open a URL, share it, draw and write together instantly. No > accounts, no teams, no paywall. Ships a public Model Context Protocol (MCP) > endpoint so AI assistants can collaborate on the same live board as humans. This Markdown file is a plain-text mirror of , served so AI fetchers (Claude WebFetch, ChatGPT browse, Perplexity, etc.) can read the page without parsing HTML. The HTML version has the same content plus styling, interactive comparison tables, and an FAQ accordion. - Canonical HTML: - Developer / MCP reference: - Machine-readable docs: · · ## What cnvs.app is cnvs.app is built for the simplest possible use case: two or more people on a call who want to sketch, write or brainstorm on the same surface. You open the site, a board is created, you copy the URL, you share it. Anyone who opens the URL joins the same canvas live. There is no signup, no login, no team setup, no board limit, no session token — just a URL and an infinite sheet of paper. The project is positioned as a minimalist alternative to Miro, FigJam, MURAL, Excalidraw and tldraw. Miro / FigJam / MURAL require accounts and paid plans for team use. Excalidraw's free tier is limited to a single scene. tldraw.com requires every participant to sign in before they can join a shared room. cnvs.app requires none of that. ## What's inside (all on the free tier) - Real-time WebSocket sync across all participants on a board. - Infinite canvas with pan (scroll) and zoom (Ctrl/Cmd/Shift+scroll, pinch). - High-definition vector drawing rendered as SVG paths. - Draggable, editable text nodes with Markdown. - Sticky-note style on any text block (right-click or hover + Y). - **Kanban task boards** — switch a fresh board to `todo` mode for columns and cards (due dates, priority, assignee, colors, multi-lane layout) instead of the free canvas. Drag cards between columns; AI agents can read and edit the same board over MCP / REST. - **Mermaid diagrams** — flowcharts, sequence, class, state, ER, Gantt, user journeys, mindmaps, timelines, git graphs, C4 — all from plain text. - Clipboard paste for images (PNG/JPEG/WebP/GIF/SVG) and URLs (rendered as clickable capsules). - Radial collision eraser + undo (Ctrl+Z) with live rebroadcast. - One-click print / PDF export with share-URL watermark. - "Hold to delete" wipes the board from the database and reserves the ID for 30 days so stale links show an "erased" overlay. - Light, dark and system themes. - Touch and mobile: two-finger pan, tap to drop text, long-press for marquee select with a Duplicate / Delete action pill. - Installable PWA with offline read-only access to cached boards. - Native MCP (Model Context Protocol) endpoint at `https://cnvs.app/mcp` so AI assistants can read and edit any board alongside humans. ## Two modes, one link Every board starts blank. Keep it freeform, or flip it to a kanban task board while it's still empty — same URL, same real-time sync, same zero signup. | Draw & Diagram — the freeform canvas | Todo & Kanban — the shared task board | |--------------------------------------|---------------------------------------| | Freehand ink in four colours (auto/red/blue/green), switchable with `1`–`4`. | One-tap switch turns an empty board into a kanban board, seeded from a starter template (kanban / sprint / bugs). | | Straight lines (hold `Ctrl/⌘`) and rectangles (hold `Alt`). | Columns you add, rename inline, recolour and drag to reorder. | | Smart connectors — line ends snap to text/images and follow them when moved. | Multi-row lanes — name each row and drag columns between lanes. | | Text nodes with Markdown — headings, bold, links, code; bare URLs auto-link. | Rich cards — name, description, due date, priority and assignee. | | Sticky notes & diagram boxes via `Y` or right-click. | Drag & drop cards within and across columns, with a live placeholder. | | Live Mermaid diagrams — flowcharts, sequence, class, ER, Gantt, mindmaps. | Done & overdue at a glance — tick complete; past-due dates flag red. | | Paste & drop images, dropped files and URL capsules. | Hover hotkeys — `Space` to complete, `Shift` for priority, `1`–`4` to colour. | | Marquee select with group move, recolour and delete. | Auto-linked URLs in descriptions and per-card title colours. | | Infinite pan & zoom, cursor-anchored, reset with `0`. | Clash-free editing — live edit locks and typing indicators. | | Eraser, one-step undo, and one-click print / PDF export. | Gentle auto-save if you wander off mid-edit, plus CSV / Markdown task export. | **Shared by both modes:** real-time WebSocket sync, live cursors, no signup, installable PWA, and full read/write access for AI assistants over MCP and the REST API (`set_board_mode`, `create_task`, `create_tasks` bulk, `move_task`, `list_tasks`, `query_tasks`, `export_tasks`). ## How cnvs.app compares | Capability | cnvs.app | Miro | FigJam | MURAL | Excalidraw | tldraw | |----------------------------------|-----------|------------------|------------------|----------|--------------------|------------------| | No signup required | Yes | No | No | No | Yes | For sharing only | | Share by URL instantly | Yes | After setup | After setup | After | Yes | Yes | | Real-time multi-user sync | Yes | Yes | Yes | Yes | Plus / self-host | Yes | | Unlimited free collaboration | Yes | No public share | 3 files | Read | 1 scene | Demo only | | Mermaid (flowcharts, sequence …) | Built in | Plugin | Plugin | No | Import only | Via AI | | Price for core collaboration | $0 forever| $8+/user/mo | $3+/user/mo | $10+/u/mo| $0 hosted (1 scene)| $0 hosted (demo) | **Pick cnvs.app** when you want to open a URL, draw on a shared canvas with whoever is on the call, and move on — no signup for anyone, no board limit, no paywall when the team grows. **Pick Miro / FigJam / MURAL** when you need templates, voting, facilitation timers, Jira/Confluence integrations, SSO. **Pick Excalidraw / tldraw** when you want a beautiful, minimal whiteboard and are willing to either sign in (tldraw rooms) or limit yourself to one scene at a time (Excalidraw free tier). ### What reviewers say > "Cnvs.app is the cleanest pick for instant, no-signup, free real-time > whiteboarding—open a board and drop a shareable link straight into a call." — [Best Free Online Whiteboards in 2026](https://innvesti.com/reports/best-free-online-whiteboards-2026/), innvesti.com, where cnvs.app is ranked **#2**. ## Collaborate with AI via MCP cnvs.app speaks the [Model Context Protocol](https://modelcontextprotocol.io) so AI assistants like Claude Desktop, Claude Code and any MCP-compatible client can read and edit the same board that you and your teammates are looking at — in real time. Strokes and text nodes the AI adds appear instantly for everyone connected, tagged with an `ai:` author label. The endpoint is `https://cnvs.app/mcp` (JSON-RPC 2.0 over HTTPS POST). No API key, no OAuth — the **board ID is the key**. Every MCP tool also has a 1:1 REST mirror at `POST /api/boards//...`, and the kanban state is a subscribable MCP resource at `cnvs://board//tasks.json`. The full developer reference — setup snippets for Claude Desktop and Claude Code, the complete tool list (`add_text`, `draw_stroke`, `set_board_mode`, `create_task`, `list_tasks`, …), real-time notifications and quotas — lives on the **Developers page**: - HTML: (sections [`#mcp`](https://cnvs.app/developers#mcp), [`#tools`](https://cnvs.app/developers#tools), [`#realtime`](https://cnvs.app/developers#realtime), [`#limits`](https://cnvs.app/developers#limits)) - Machine-readable: · · ## Privacy & security - **No AI training on your content.** We do not use the contents of your boards to train AI models, ours or anyone else's. - **No activity logging.** No analytics on what you draw, no content logging, no tracking cookies, no fingerprinting. - **Delete is permanent.** Hold-to-delete or 30-day inactivity expiry irreversibly destroys content with no backup. - **Unlisted by design.** Boards are reachable only by URL. No public gallery, no search index, no "explore" feed. - **Optional PIN lock.** Any board can be locked with a short access key from the padlock in the toolbar — a write-lock (public view, key-holders edit) or a full read + write lock; the key is stored hashed. Finer-grained access (domain-lock, magic-link, one-time code) is on the roadmap. - **TLS end-to-end.** Hosted on Cloudflare's edge network. - **Not open source.** We run the service ourselves so the privacy guarantees can actually be enforced. ## Retention Boards are kept for up to **30 days of inactivity**. "Inactivity" means nobody has *read* the board (browser load, `GET /json/`, MCP `get_board`) in 30 days. Writes, SVG/PNG thumbnails, unfurl bots and long-poll waits do NOT reset the clock — only a real read does. After 30 days the contents are purged and the ID is released. If you hold-to-delete a board yourself, the ID is reserved for 30 days so stale links show an "erased" overlay instead of silently creating a new board. ## FAQ (deep links) Each answer has a stable anchor under : - [`#faq-free`](https://cnvs.app/about#faq-free) — Is cnvs.app really free? - [`#faq-account`](https://cnvs.app/about#faq-account) — Do I need an account? - [`#faq-retention`](https://cnvs.app/about#faq-retention) — How long are boards kept? - [`#faq-vs-miro`](https://cnvs.app/about#faq-vs-miro) — vs Miro / FigJam / MURAL? - [`#faq-vs-excalidraw`](https://cnvs.app/about#faq-vs-excalidraw) — vs Excalidraw / tldraw? - [`#faq-privacy`](https://cnvs.app/about#faq-privacy) — Is my data private? - [`#faq-delete`](https://cnvs.app/about#faq-delete) — What happens after I delete a board? - [`#faq-mobile`](https://cnvs.app/about#faq-mobile) — Does it work on mobile / tablet? - [`#faq-offline`](https://cnvs.app/about#faq-offline) — Does it work offline? - [`#faq-mcp`](https://cnvs.app/about#faq-mcp) — Can I connect Claude / an AI to a board? - [`#faq-kanban`](https://cnvs.app/about#faq-kanban) — Can it be used as a kanban / todo board? - [`#faq-storage`](https://cnvs.app/about#faq-storage) — Where is the data stored? ## Made by CODER AI cnvs.app is built and operated by CODER AI (), maker of several free productivity tools: - [plugand.ai](https://plugand.ai) — whole-team Slack AI bot, no per-seat. - [plai.chat](https://plai.chat) — private AI chat, 300+ models. - [maxcv.ai](https://maxcv.ai) — AI CV tailored to each job, ATS-optimised. - [free-sign.com](https://free-sign.com) — Sign PDFs confidentially in your browser. No upload. No account. - [whenmeet.me](https://whenmeet.me) — cross-company group scheduling + video. - [mcpfinder.dev](https://mcpfinder.dev) — open-source MCP discovery for agents. Each tool publishes its own agent docs — append /llms.txt to any URL above. Last updated: 2026-06-08.