Free online developer tools

4 tools

Small utilities developers reach for daily: JSON and YAML formatters, Base64 and URL encoders, regex testers, JWT decoders, diff viewers and cron helpers. Prefer tools marked as running in your browser when you paste tokens, keys or production data, because nothing is uploaded.

Showing 1–4 of 4

0.478score
Local Directory Explorer
Simon Willison
Lets you pick a local folder and browse and search its file tree in the browser.
ArtifactNo sign-upIn-browserdeveloper tools
0.477score
Keyboard Debugger
Simon Willison
Displays key names and key codes for each key you press.
ArtifactNo sign-updeveloper tools
0.477score
Passkey Demo
Simon Willison
Try registering and signing in with WebAuthn passkeys right in the browser.
ArtifactNo sign-updeveloper tools
0.477score
Rich Text HTML Extractor
Simon Willison
Shows the HTML source behind formatted text you paste into the page.
ArtifactNo sign-updeveloper tools