Free Online Developer Tools
43+ tools for formatting, converting, encoding, generating & more. All data is processed in your browser — nothing is sent to any server.
JSON formatter, Base64 encoder, UUID generator, regex tester, hash generator, cron parser, diff checker — all in one place, always free, always private.
Browse All ToolsWhy Use DevToolHub?
100% Private
Every tool runs entirely in your browser. Your data never leaves your device — no server uploads, no tracking, no logs. Perfect for working with sensitive API keys, tokens, and production data.
Instant Results
No waiting for server responses. Paste your input, click transform, get your output — all in milliseconds. Built as a static site with zero backend latency. Pages load fast even on slow connections.
Free Forever
No sign-up, no usage limits, no premium tiers. Every tool is free to use as many times as you need. Bookmark the ones you use most and come back anytime.
Works Everywhere
Desktop, tablet, or phone — every tool is responsive and works in all modern browsers. Need to quickly decode a JWT on your phone? No problem.
All-in-One Toolkit
Stop juggling between different sites for different tools. JSON formatting, Base64 encoding, UUID generation, regex testing, hashing, cron parsing, diff checking — everything a developer needs in one place.
Learn While You Use
Each tool comes with clear explanations, step-by-step guides, and FAQ sections. Not sure what a cron expression does or how Base64 works? Read the guide right on the tool page.
How It Works
- 1
Pick a tool
Browse categories or use the tools index to find what you need — JSON tools, encoders, generators, converters, and more.
- 2
Paste your input
Paste text, JSON, code, or whatever the tool accepts. Some tools like UUID Generator or Password Generator don't need any input at all.
- 3
Get instant results
Click the action button and get your output immediately. Copy to clipboard or download as a file — all processed locally in your browser.
Popular Tools
JSON Formatter & Beautifier
Format, beautify, and pretty-print JSON data online. Choose indentation style, copy or download the result. Free, fast, and private.
Base64 Encoder
Encode any text to Base64 online. Supports UTF-8 characters including accents, CJK text, and emoji. Free, fast, client-side.
Base64 Decoder
Decode Base64 strings back to plain text online. Handles standard Base64 and UTF-8 encoded content. Free, fast, client-side.
UUID Generator
Generate random UUIDs (v4) and sortable UUIDs (v7) instantly. Copy single or batch-generate multiple UUIDs at once.
Regex Tester & Debugger
Free online regex tester. Test regular expressions in real time with match highlighting, capture groups, and flag toggles — all in your browser.
JSON Validator
Validate your JSON data instantly. Check for syntax errors, see detailed error messages, and get document statistics.
Cron Expression Parser & Generator
Parse, validate, and generate cron expressions online. See human-readable schedule descriptions and next execution times instantly.
Tool Categories
JSON Tools
Format, validate, view, and convert JSON data with free online tools.
4 tools →Encoders & Decoders
Encode and decode Base64, URL, JWT, HTML entities and more.
13 tools →Code Formatters
Beautify and format SQL queries and other code online.
1 tool →Generators
Generate UUIDs, passwords, Lorem Ipsum, hashes and more.
3 tools →Data Converters
Convert between JSON, CSV, and YAML formats online.
2 tools →Text Utilities
Diff checker, word counter, case converter, slug generator and more.
15 tools →Date & Time
Unix timestamp converter and cron expression parser.
2 tools →Hash & Crypto
Generate MD5 and SHA-256 hashes for checksums and integrity verification.
1 tool →Regex
Test and debug regular expressions with real-time matching.
1 tool →Color Tools
Convert between HEX, RGB, HSL color formats and pick colors.
1 tool →