About FA Dev Tools
Free, fast developer tools that run in your browser.
Our Mission
FA Dev Tools collects the small utilities developers reach for every day, such as formatters, converters, encoders, generators and quick references, in one place with no sign-up. Most tools run entirely in your browser, so what you paste stays on your device.
What We Offer
Text and JSON tools
Format, validate, compare, extract and convert JSON, tables and plain text.
Encoders and generators
Base64, URL, HTML and JSON string codecs, plus UUID and password generators.
Date, time and units
Time zones, date formats, pixel and pressure calculators, and more.
AI helpers
Explain, summarise and improve English text with AI assistance.
Quick references
Linux, macOS and Windows commands, shortcuts and software lists.
Your workspace
Sign in with Google to keep bookmarks, documents and settings across devices.
Who It's For
Developers
Frontend, backend and full-stack developers who want a tool open in one click.
Testers and support
Anyone who needs to inspect, decode or compare data quickly.
Who We Are
cityuderek.com is run by FishApple, based in Hong Kong. It is free to use. Ads, shown only if you allow them, help pay for it.
Get in Touch
Questions, bug reports and ideas for new features are all welcome. Email [email protected] or see the Contact Us page.