StackBlitz
A browser development environment for starting, running, sharing, and debugging web and Node.js projects.
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Can I Use
Searchable browser-support tables for HTML, CSS, JavaScript APIs, and other modern web platform features.
Crontab Guru
A quick cron-expression editor that translates schedules into plain language and shows upcoming run times.
Mergely
A browser-based side-by-side diff and merge editor for comparing text, source code, and local files.
regex101
An interactive regular-expression tester with explanations, match details, debugging, and reusable test cases.
Hoppscotch
An open-source API development client for composing, sending, organizing, and testing requests in the browser.
WebAIM Contrast Checker
A focused accessibility checker for measuring foreground and background color contrast against WCAG thresholds.
Have I Been Pwned
A public breach lookup service for checking whether an email address appears in known compromised datasets.
IT-Tools
A searchable collection of browser utilities for developers and people working in IT.
Ray.so Code Images
A focused browser tool for styling a code snippet and exporting it as an image.