Free Online Developer Tools - No Upload, No Account

No Server. Just Tools. The ultimate suite of WASM-powered tools for developers who care about privacy. No cloud, no leaks, no latency.

Our Privacy-First Developer Tools

Format

JSON Formatter

Prettify, minify, and validate JSON data with syntax highlighting.

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Security

JWT Debugger

Decode and inspect JWT tokens with privacy-first local processing.

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Documents

PDF Workbench

Secure, local-only PDF tools. Merge multiple files, split pages, and protect documents.

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Media

Image Optimizer

All-in-one client-side image optimization and conversion tool with privacy-first processing.

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Media

Image Resizer

Resize and crop images locally with high quality and precise fit modes.

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Media

SVG Studio

Optimize SVG files and generate React components with Tailwind CSS support.

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Media

Image Cropper

Interactive, safe, local pixel extraction using visual freeform cropping.

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Development

DevShot

Generate beautiful code screenshots with syntax highlighting and custom themes.

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Development

Data Transformer

Convert CSV and Excel spreadsheets to JSON, SQL, HTML, and Markdown securely in your browser.

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Development

UUID Generator

Generate cryptographically secure UUID v4 identifiers locally using the Web Crypto API. No server.

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Development

Base64 Encoder & Decoder

Encode text and files to Base64 or decode Base64 strings, entirely in your browser. URL-safe support.

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Format

JSON ↔ YAML

Bidirectional JSON to YAML and YAML to JSON converter. Runs locally — safe for configs with secrets.

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Developer Guides

All guides
JWT

How to Debug a JWT Token Locally

Decode JWT payloads, inspect claims, check expiration, and verify signatures — entirely in your browser.

Read guide Format

JSON vs YAML: Key Differences

Side-by-side syntax comparison, common pitfalls like the Norway problem, and when to choose each format.

Read guide Media

Compress Images for the Web

Formats, quality targets, LCP optimization tips, and the <picture> element — without uploading anything.

Read guide Encoding

Base64 Encoding Explained

The algorithm, data URIs, JWTs, HTTP Basic Auth — and why Base64 is not encryption.

Read guide JSON

How to Format and Validate JSON

JSON syntax rules, the 10 most common errors, and how to fix them — with code examples.

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