Developer Tools
Free developer utilities for JSON formatting, Base64 encoding, JWT decoding, regex testing, UUID generation, hash computation, cron building, and more. Paste, convert, copy — all client-side.
Twelve browser-based developer utilities designed for the tasks you do every day: formatting a messy JSON response, decoding a JWT during auth debugging, testing a regex against sample data, generating UUIDs for database records, computing file checksums, and building cron schedules. Every tool processes data client-side using standard Web APIs — your tokens, payloads, and keys never leave your machine. No npm installs, no CLI setup, no server round-trips.
2 "api": "v2.1",
3 "status": 200,
4 "ok": true
5 }
a1b2c3d4-e5f6-7890-abcd-ef12JSON Formatter & Validator
Format, validate, and prettify JSON instantly.
DeveloperBase64 Encode & Decode
Encode text to Base64 or decode Base64 to text.
DeveloperJWT Decoder
Decode and inspect JSON Web Tokens instantly.
DeveloperTimestamp Converter
Convert between Unix timestamps and human-readable dates.
DeveloperRegex Tester
Test and debug regular expressions with real-time matching.
DeveloperUnit Converter
Convert between units of length, weight, temperature, and more.
DeveloperUUID/ULID Generator
Generate UUIDs (v4) and ULIDs instantly with bulk support.
DeveloperURL Encoder/Decoder
Encode or decode URLs and query string components.
DeveloperHash Generator
Generate SHA-1, SHA-256, SHA-512, and MD5 hashes from text or files.
DeveloperColor Converter
Convert colors between HEX, RGB, HSL, and OKLCH formats.
DeveloperCron Expression Builder
Build and decode cron expressions with a visual interface.
Developerchmod Calculator
Calculate Unix file permissions in symbolic and octal notation.
DeveloperText Diff Tool AI
Compare two texts and see differences highlighted line by line.
DeveloperJSON to CSV Converter
Convert JSON arrays to CSV with delimiter and flattening options.
DeveloperNumber Base Converter
Convert numbers between binary, octal, decimal, hexadecimal, and more.
DeveloperIP Address & CIDR Calculator
Calculate subnet details from any IPv4 address and CIDR prefix.
DeveloperString Similarity (Levenshtein)
Compare two strings and see Levenshtein edit distance, similarity score, and step-by-step operations.
DeveloperMermaid Chart Editor
Create, preview, and export Mermaid diagrams with live rendering and syntax error detection.
DeveloperHTML Entity Encoder & Decoder
Encode special characters to HTML entities or decode entities back to text.
DeveloperJSON to TypeScript Converter
Paste JSON and instantly get TypeScript interfaces with inferred types.
DeveloperJSON to YAML Converter
Convert between JSON and YAML formats instantly.
DeveloperSQL Formatter & Validator
Format and beautify SQL queries with dialect support.
DeveloperXML to JSON Converter
Convert between XML and JSON formats with attribute handling.
DevelopercURL to Code Converter
Convert cURL commands to code in 8 programming languages.
DeveloperCode Playground
Write HTML, CSS, and JavaScript with live preview.
DeveloperAPI Request Builder
Build and send HTTP requests right from your browser.
DeveloperSnippet Manager
Save, organize, and search your code snippets.
DeveloperRobots.txt Generator
Generate and validate robots.txt files with a visual rule builder.
DeveloperSchema Markup Generator
Generate JSON-LD structured data for Google rich results.
DeveloperOpen Graph Tag Generator
Generate Open Graph and Twitter Card meta tags with live social previews.
DeveloperFrequently Asked Questions
- Are these tools safe for sensitive data like JWTs and API keys?
- Yes. All processing happens in your browser. Your data is never sent to any server or logged. The JWT Decoder, for example, decodes the token structure locally and clears everything when you close or refresh the page.
- Which browsers are supported?
- All modern browsers — Chrome, Firefox, Safari, and Edge. Tools use standard Web APIs (TextEncoder, crypto.getRandomValues, SubtleCrypto) so no extensions or plugins are needed.
- Can I use these tools offline?
- Once the page loads, most tools work without an active internet connection because all logic runs client-side. The initial page load requires connectivity.
- How does the Hash Generator work for files?
- The Hash Generator reads your file entirely in the browser using the FileReader API, then computes SHA-1, SHA-256, SHA-384, SHA-512 via the Web Crypto SubtleCrypto API, and MD5 via a pure-JavaScript implementation. The file is never uploaded anywhere.
Related Guides
View allA Developer's Debugging Toolkit: JSON, JWT, Regex, and Beyond
A practical workflow guide for developers who debug API responses, authentication tokens, and data formats daily. Learn how to use browser-based tools to inspect JSON, decode JWTs, test regex patterns, and more — without exposing sensitive data to third-party servers.
The DevOps and Backend Toolkit: Encoding, Networking, SQL, and Diagrams in the Browser
A comprehensive guide to browser-based tools that streamline backend and DevOps workflows, from IP subnet calculation and chmod permissions to SQL formatting, encoding utilities, and diagram creation.
When to Use These Tools
These developer tools are designed for the quick, repetitive tasks that interrupt your flow during coding sessions. Instead of opening a terminal, installing a package, or writing a throwaway script, paste your data into the browser and get results instantly.
Common scenarios: debugging a malformed JSON response from an API, decoding a JWT to check token claims during authentication work, testing a regex pattern against sample log data, generating UUIDs for a database migration script, computing a file hash to verify download integrity, or building a cron expression for a CI/CD pipeline. Every tool keeps your data local — critical when working with production tokens, API keys, or customer data.
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