marmelab/gremlins.js

Health v2 · maintenance only

Adoption not part of the score

9091 stars · 424 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

gremlins.js is a JavaScript monkey testing library for Node.js and the browser that unleashes random user-like actions (clicking, typing, scrolling, form filling, touching) on a web app to test its robustness. It includes 'mogwai' watchers that monitor console errors and frame rates to detect errors, performance problems, and memory leaks.

Use cases

• stress test a web app with random clicks and typing
• detect memory leaks in frontend JavaScript
• find unhandled errors in a web application
• run chaos/monkey testing in Cypress or Playwright
• check robustness of an HTML5 app before release

When to choose

• you want randomized, unscripted stress testing of a browser-based frontend
• you need to surface crashes, console errors, or performance degradation from unpredictable user behavior
• you want a lightweight library that integrates with Cypress or Playwright

When to avoid

• you need deterministic, assertion-based unit or e2e tests
• you are testing non-browser backend code
• you need actively maintained tooling with frequent updates

Facets

library · maturity maintenance

testing fuzzing benchmarking testing web-development frontend developer-tools browser monkey-testing chaos-testing stress-testing bookmarklet cypress playwright nodejs javascript

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