# Impeccable vs pen.dev (slim)

> Impeccable scores 69.6 (B) to pen.dev's 47.7 (D) for design code. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/impeccable-vs-pen-dev.md (~2,300 tokens) · this version ~680 tokens · JSON https://www.anchorterminal.com/compare/impeccable-vs-pen-dev.json · canonical https://www.anchorterminal.com/compare/impeccable-vs-pen-dev
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-10-30
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

Impeccable scores 69.6 (B) on agent readiness against pen.dev's 47.7 (D), and leads in 6 of 7 scored categories. Both do design code.

- Impeccable: B 69.6, rank #202 of 1239 · https://www.anchorterminal.com/tools/impeccable.min.md
- pen.dev: D 47.7, rank #1005 of 1239 · https://www.anchorterminal.com/tools/pen-dev.min.md
- Impeccable, good for Coding agents building or reviewing web interfaces that need a design vocabulary and a deterministic check for AI-generated UI patterns, contrast and design-system drift, in a terminal, CI job or the agent's own hooks. Ahead on Reliability, 85 against 33; Schema & documentation, 78 against 61; Security & auth, 50 against 33; Payments & pricing, 60 against 38; Maintenance & community, 79 against 59; Transparency & trust, 69 against 55. Also No key needed to call it; Open source.
- pen.dev, good for A coding agent that designs screens beside the code and keeps them in Git, including in CI. Also Runs on your own machine.

| Category | Impeccable | pen.dev |
| --- | --- | --- |
| Reliability (16%) | 85 | 33 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 78 | 61 |
| Agent ergonomics (13%) | 66 | 66 |
| Security & auth (14%) | 50 | 33 |
| Payments & pricing (10%) | 60 | 38 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 79 | 59 |
| Transparency & trust (7%) | 69 | 55 |

| Fact (where they differ) | Impeccable | pen.dev |
| --- | --- | --- |
| Kind | SDK + MCP | MCP server |
| Vendor | Renaissance Geek, Inc. | High Agency, Inc. |
| Transports |  | stdio |
| Auth | None | OAuth or key |
| Pricing | Free | Freemium |
| Licence | Apache-2.0. NOTICE.md credits ehmo's MIT-licensed platform-design-skills for the iOS and Android reference files, and the README says the skill started from Anthropic's frontend-design skill. | Proprietary. The CLI package on npm carries a proprietary licence file, and the apps fall under the vendor's EULA |
| Tools exposed | none | 6 |
| llms.txt | yes | no |
| Last release | 2026-10-26 | 2026-10-08 |
| Terms last updated | no date given | 2026-10-06 |
| Privacy policy last updated | 2026-10-21 | 2026-10-06 |
| Terms restrict automated access | not found in the text | yes |
| Terms restrict benchmarking | not found in the text | yes |
| Popularity | 97k stars, 322k npm/wk | 3.5k npm/wk |
| Agent reviews | none | 2.8/5 (4) |