# Excalidraw vs Kroki

> Kroki scores 59.2 (C) to Excalidraw's 54.5 (C) for diagram creation. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/excalidraw-vs-kroki
- Markdown: https://www.anchorterminal.com/compare/excalidraw-vs-kroki.md (~2,550 tokens)
- Slim: https://www.anchorterminal.com/compare/excalidraw-vs-kroki.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/excalidraw-vs-kroki.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

Kroki scores 59.2 (C) on agent readiness against Excalidraw's 54.5 (C), and leads in 4 of 7 scored categories. Excalidraw leads on schema & documentation and security & auth. Both do diagram creation.

- Excalidraw: grade C, 54.5/100, rank #683 of 950. Markdown https://www.anchorterminal.com/tools/excalidraw.md · JSON https://www.anchorterminal.com/api/v1/tools/excalidraw.json
- Kroki: grade C, 59.2/100, rank #558 of 950. Markdown https://www.anchorterminal.com/tools/kroki.md · JSON https://www.anchorterminal.com/api/v1/tools/kroki.json
- Best diagramming APIs and diagram-as-code for AI agents: https://www.anchorterminal.com/best/diagramming/index.md
- All 99 diagrams comparisons: https://www.anchorterminal.com/compare/diagramming/index.md

## Which one, for what

### Excalidraw (C)

Good for: Teams already on Excalidraw+ that want agents to create and edit hand-drawn diagrams, slides and wireframes in a shared workspace, and one-off sketches through the free MCP App.

Ahead on:
- Schema & documentation, 65 against 48
- Security & auth, 73 against 56

Also in its favour:
- A hosted endpoint, with nothing to install

Watch for: The API and MCP server are in public beta. The docs say endpoints, tool names and schemas may change and to expect breaking changes

### Kroki (C)

Good for: Agents that write diagrams in several text formats and want one render endpoint, on a private network or through the public instance for non-sensitive diagrams.

Ahead on:
- Reliability, 74 against 50
- Agent ergonomics, 70 against 58
- Payments & pricing, 60 against 35
- Maintenance & community, 86 against 44

Also in its favour:
- No key needed to call it

Watch for: GHSA-wmpp-fj9c-w766 (CVSS 9.8) allowed unauthenticated remote code execution on `/tikz/svg` in versions 0.21.0 up to 0.32.0, whatever the safe mode. Fixed 3 August 2026


## Score by category

| Category | Weight | Excalidraw | Kroki | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 50 | 74 | Kroki +24 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 65 | 48 | Excalidraw +17 |
| Agent ergonomics | 13% (16.2 this run) | 58 | 70 | Kroki +12 |
| Security & auth | 14% (17.5 this run) | 73 | 56 | Excalidraw +17 |
| Payments & pricing | 10% (12.5 this run) | 35 | 60 | Kroki +25 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 44 | 86 | Kroki +42 |
| Transparency & trust | 7% (8.8 this run) | 63 | 62 | Excalidraw +1 |
| Negative events | ≤15 | -2 | -5 | |
| **Total** | | **54.5 · C** | **59.2 · C** | |

## Facts side by side

| Fact | Excalidraw | Kroki |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Excalidraw s.r.o. | Yuzu tech |
| Hosted endpoint | `https://api.excalidraw.com/api/v1/mcp` | no (local only) |
| Transports | HTTP, Streamable HTTP | HTTP |
| Auth | API key | None |
| Pricing | Freemium | Free |
| x402 | no | no |
| Licence | Excalidraw+ is a proprietary service under Excalidraw's terms of use. The editor and the MCP App on GitHub are MIT | MIT |
| Tools exposed | 37 | none |
| Read-only variant documented | no | no |
| llms.txt | yes | no |
| Last release | 2026-09-01 | 2026-10-05 |
| Terms last updated | no date given | no document linked |
| Privacy policy last updated | 2021-04-29 | no document linked |
| Customer content may train models | not found in the text |  |
| Terms restrict automated access | yes |  |
| Terms restrict benchmarking | not found in the text |  |
| Terms or service can change without notice | yes |  |
| Arbitration or class-action waiver | yes |  |
| Popularity | 134k stars, 676k npm/wk | 4.4k stars |

## Verdicts

**Excalidraw.** Excalidraw+ keys carry read or full permission, route restrictions and an expiry, and the MCP server shows a key only the tools its routes allow. The API and MCP server are in public beta with breaking changes expected, sit behind the $6 Plus plan, and have no published OpenAPI file, SDK or idempotency keys.

**Kroki.** One unauthenticated POST with diagram text returns an image for 29 diagram types, and five versions shipped between 15 July and 5 October 2026. Four advisories were published in July and August 2026, one an unauthenticated remote code execution on `/tikz/svg`, all fixed. No OpenAPI file exists, and the public instance has no terms, privacy policy or status page.

## Before you call either

### Excalidraw

1. Send `Authorization: Bearer <API_KEY>` to https://api.excalidraw.com/api/v1. For MCP, use `POST /api/v1/mcp` only. The server is stateless and answers 405 to other methods
2. Use a personal key to reach the owner's private collection with the collection ID `private`. A workspace admin must enable personal keys first
3. Call `read_diagram_format`, `read_presentation_format` or `read_freeform_format` before the first scene write in a session
4. Write with `edit_scene_content` and bind arrows through `startBinding` and `endBinding` with `tempId` references. `PUT /scenes/{sceneId}/content` removes every element left out of the request
5. Stay under 600 requests a minute per IP and wait until `X-RateLimit-Reset` after a 429

### Kroki

1. Send `POST /<type>/<format>` with `Content-Type: text/plain` and the diagram as the body. This avoids the deflate and base64 encoding that GET needs
2. Send `Accept: application/json` on a JSON request to get errors as `{"error": {"code", "message"}}`. With an SVG Accept header the error arrives as an image
3. Call `GET /health` first to list the diagram types and library versions the instance has. Mermaid, BPMN, Excalidraw and diagrams.net need companion containers
4. Run 0.32.1 or later before rendering untrusted text. Earlier versions allow remote code execution through `/tikz/svg` and file reads in `SECURE` mode
5. Self-host for private diagrams with `docker run -p8000:8000 yuzutech/kroki`, and set `KROKI_LISTEN=127.0.0.1:8000` or a network rule, since the server has no authentication

## Questions

### Which is better for AI agents, Excalidraw or Kroki?

Kroki scores 59.2 (C) on agent readiness against Excalidraw's 54.5 (C), and leads in 4 of 7 scored categories. Excalidraw leads on schema & documentation and security & auth.

### Do Excalidraw and Kroki need an API key?

Excalidraw needs an API key. Kroki needs no key.

### Can an agent call Excalidraw and Kroki without installing anything?

Excalidraw has a hosted endpoint at https://api.excalidraw.com/api/v1/mcp. No hosted endpoint is listed for Kroki.

### Are Excalidraw and Kroki open source?

Yes. Excalidraw is open source (Excalidraw+ is a proprietary service under Excalidraw's terms of use. The editor and the MCP App on GitHub are MIT). Kroki is open source (MIT).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/excalidraw-vs-kroki.json, and with the fewest tokens: https://www.anchorterminal.com/compare/excalidraw-vs-kroki.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "excalidraw", "b": "kroki"}`. From a terminal: `anchor compare excalidraw kroki`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/excalidraw.json and https://www.anchorterminal.com/api/v1/tools/kroki.json

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