Free Developer Tools Online
Inspect and transform common developer data without setting up a project, or create a permitted offline archive of a public website. These focused utilities are designed for quick debugging, verification and static capture work.
All developer & tech tools
Choose the focused utility that matches the result you need.
JSON Formatter
Format, minify and validate JSON with clear browser-side errors.
Base64 Tool
Encode Unicode text to Base64 or decode it back safely.
URL Encoder
Encode query values and decode percent-escaped URLs instantly.
JWT Decoder
Inspect JWT header and payload claims locally without verification.
Timestamp Converter
Convert Unix seconds, milliseconds and human-readable dates.
UUID Generator
Generate secure UUID v4 identifiers in configurable batches.
Regex Tester
Test patterns, flags and matches against sample text as you type.
Website Downloader
Download reachable pages, images, CSS, JavaScript, fonts and other site assets as one organized ZIP.
Contact Widget
Build a branded WhatsApp and Messenger button, preview it live and copy the website embed code.
How to choose the right tool
Start with the result the next step in your workflow expects. A smaller purpose-built utility is usually easier to test and explain.
- Do not paste production secrets into any utility.
- Remember that decoding a JWT does not verify its signature.
- Test transformed output in the system that will consume it.
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About this collection
Are these developer & tech tools free?+
Yes. Every core tool in this collection can be used without payment or account registration.
Do the tools work on phones and computers?+
They are designed for current mobile and desktop browsers. Test important event, export or print workflows on the device you will actually use.
Is an account required?+
No. An optional account adds private history, but it does not unlock the core tool experience.