Free Browser-Based Developer Tools
Quick transformations, inspections and public-site captures should not require a new repository or command-line setup. These tools cover common developer scratch work and organized offline archives.
Choose a tool and start
Every core workflow is free and available without creating an account.
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.
What to check
- Never paste secret keys or sensitive production payloads.
- Distinguish decoding from validation or signature verification.
- Test edge cases before using transformed data in production.
From input to result
- 01
Choose the utility that matches the data format.
- 02
Paste a safe sample and inspect validation feedback.
- 03
Copy the result and verify it in the target system.
Related tool topics
About this topic
What is included in this developer tools collection?+
This page brings together 8 focused ToolMaster utilities that support the same task or workflow.
Can I use these tools without signing up?+
Yes. The core workflow of every listed tool is free and available without an account.
How should I choose between the tools?+
Start with the output you need, read the short description on each card and test the result in its final destination before relying on it.