head to head · open source
ECC vs Onlook
ECC has 263,046 GitHub stars, 39,368 forks, 204 open issues and last shipped today. Onlook has 26,766 stars, 2,106 forks, 380 open issues and last shipped 26 days ago. ECC leads on adoption by 883% (263,046 vs 26,766 stars). ECC is written in JavaScript under MIT; Onlook is written in TypeScript under Apache-2.0. ECC has attracted 15% as many forks as stars, Onlook 8%. ECC was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| ECC | Onlook | |
|---|---|---|
| GitHub stars | ★ 263K | ★ 27K |
| License | MIT | Apache-2.0 |
| Written in | JavaScript | TypeScript |
| Last push | 2026-09-20 | 2026-08-25 |
| Forks | ⑂ 39K | ⑂ 2.1K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick ECC if
- You weight community size — 263K stars and counting
- You want the MIT license terms
- Your stack matches JavaScript
- You value the larger contributor base for long-term maintenance
pick Onlook if
- You want the Onlook feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches TypeScript
- You evaluated both and Onlook fits your workflow better
About ECC
ECC is an MIT licensed open source agent harness performance optimization system that gives AI coding agents a coordinated engineering workflow — plan, test, implement, review, verify, remember, improve — for developers working in Claude Code, Codex, OpenCode, Cursor, and other harnesses.
About Onlook
Onlook is an open source, Apache 2.0 visual editor for Next.js and TailwindCSS projects that lets designers and developers edit a running React app in the browser while the underlying code changes in real time.
read the full Onlook overview →
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Frequently asked questions
Is ECC or Onlook more popular?
ECC has 263,046 GitHub stars and Onlook has 26,766. ECC has the larger community by that measure.
Are ECC and Onlook free?
Both are open source. ECC is licensed under MIT and Onlook under Apache-2.0. Neither carries a licence fee.
What is the difference between ECC and Onlook?
ECC is written in JavaScript and Onlook in TypeScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, ECC or Onlook?
Choose ECC if you want the larger community (263,046 stars) or its MIT licence terms. Choose Onlook if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.