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About BasaltKit

Free browser-based developer tools, with clear handling of inputs, files and network requests.

Why BasaltKit exists

Most online tools quietly upload your data to a server, process it there, and show you the result. That is unnecessary for most everyday tasks — formatting JSON, converting data, hashing a string or decoding a token can all be done with code that runs in your own browser.

BasaltKit provides 89 browser-based tools. Local utilities process your input on this device; API Tester sends requests directly to your chosen target. Pages, dependencies, analytics and advertising require network access. Offline use depends on which resources have loaded. See the privacy and storage policy for details.

What's inside

  • JSON Tools — JSON Formatter & Validator, JSON Diff Checker, JSON to TypeScript, JSON to Go Struct, JSON to Python Class, JSON to Java Class, JSON to C# Class, JSON to PHP Class, JSON to Rust Struct, JSON to YAML Converter, XML to JSON Converter, JSON to XML Converter, TOML to JSON Converter, YAML to JSON Converter, JSON Flatten / Unflatten.
  • Images — QR Code Generator, Image Compressor, Image Resizer, Image Cropper, Add Text to Image, Photo Collage Maker, HEIC to JPG, Image Converter, Favicon Generator, SVG to PNG, Image to Base64, Base64 to Image.
  • PDF Tools — PDF to JPG, Merge PDF, Split PDF, JPG / PNG to PDF, PDF Page Organizer.
  • Audio & Video — Media Info (ffprobe), Video Converter, Video Compressor, Video Trimmer, Video to GIF, Extract Audio from Video, Audio Converter.
  • Encode & Crypto — Base64 Encode / Decode, Password Generator, Hash Generator, UUID Generator, JWT Decoder, Encode / Decode, AES-256 Encrypt / Decrypt, Unicode Converter, Gzip Compress / Decompress, HMAC Generator, Barcode Generator, Password Strength Checker, TOTP Generator (2FA), Certificate Decoder, Base32 Encoder / Decoder.
  • Formatters — URL Encode / Decode, SQL Formatter, XML Formatter & Minifier, CSS Formatter & Minifier, URL & Query String Parser, HTTP Header Formatter, Cookie Parser & Formatter.
  • Text — Case Converter, Text Toolkit, Lorem Ipsum Generator, Markdown ⇄ HTML Converter, Slug Generator, Batch Find & Replace.
  • Developer — Timestamp Converter, Regex Tester, Color Converter, Cron Expression Generator, Subnet Calculator, Number Base Converter, cURL to Code, API Tester (HTTP Client), HTTP Status Codes, MIME Types Reference, Chmod Calculator, ASCII Table, User-Agent Parser.
  • CSV — CSV to JSON Converter, JSON to CSV Converter, CSV Merger, CSV Validator, CSV Deduplicator, Delimiter Detector, CSV to SQL, CSV to Markdown Table.
  • Printables — Printable Paper Generator.

The principles

  • Clear data handling. Local input processing and intentional network requests are labelled on each tool.
  • No signup. Open the page, use the tool, get on with your day.
  • Fast and light. Static pages with additional dependencies loaded when a tool needs them.
  • Honest output. Clear errors with exact positions, no silent guessing.

License & copyright

BasaltKit's code, design and written content are © 2026 BasaltKit — all rights reserved. You are welcome to use every tool on this site freely, and to quote short excerpts with attribution and a link back to the original page. Copying, mirroring or reusing this site's code, design or content to build or operate another website or product is not permitted. The BasaltKit name and logo are trademarks of BasaltKit. For licensing enquiries, contact support@basaltkit.com.

Contact

Feedback, bug reports and tool requests are welcome at support@basaltkit.com.