Format and inspect code
Make code and payloads readable, validate their structure and explore nested data.
18 focused tools
Free Online Developer Tools
Format, validate, convert and inspect code or structured data without opening a full IDE. Choose a focused utility for JSON, SQL, regex, JWTs, hashes, encoders and everyday development tasks.
Core formatting, encoding and generation tasks run locally in your browser.
No sign-up required
All Developer tools
Choose a tool directly or filter the collection by task.
JSON Formatter & Validator
Format, beautify, minify, and validate JSON data
JSON to CSV Converter
Convert JSON arrays to Comma-Separated Values (CSV) formats
XML to JSON Converter
Format, parse, and convert between XML and JSON documents safely
SQL Formatter & Beautifier
Format unreadable inline SQL queries with proper indentation
CSS Minifier & Beautifier
Minify CSS for production or beautify it for readability
JWT Decoder
Decode JSON Web Tokens, inspect header/payload, and check expiration
Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 strings
HTML Entity Encoder / Decoder
Convert special characters like < to &lt; or decode them back
URL Encoder / Decoder
Encode or decode special characters in URLs
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes for text and files
Regex Tester & Matcher
Test your expressions against strings in real-time with highlighting
Cron Job Generator
Generate or parse cron expressions into human-readable text
Markdown Preview
Write GitHub-Flavored Markdown and preview rendered HTML instantly
YAML to JSON Converter
Convert YAML config files to JSON, and back again, instantly
CSV to YAML Converter
Convert CSV spreadsheets into structured YAML, and back again
.gitignore Generator
Generate a custom .gitignore file for any language, framework, or IDE
JSON Tree Viewer
Explore deeply nested JSON as a collapsible, editable tree
Code Beautifier & Minifier
Beautify or minify HTML, CSS, and JavaScript in one place
No tools match that search. Try a shorter task or format name.
Find the right tool by task
Start with what you need to accomplish, then open the most specific tool.
Convert structured data
Move data between JSON, CSV, XML and YAML formats for APIs, configs and spreadsheets.
Encode, decode and secure
Inspect tokens, encode transport-safe strings and create checksums or hashes.
Test and generate
Test patterns and create configuration snippets without leaving the browser.
Quick pick
Which tool should I use?
Choose the result you need and jump straight to the right tool.
JSON Formatter & Validator
Validate or pretty-print an API payload
Format, beautify, minify, and validate JSON data
Code Beautifier & Minifier
Beautify or minify HTML, CSS and JavaScript together
Beautify or minify HTML, CSS, and JavaScript in one place
Regex Tester & Matcher
Test a regular expression against sample text
Test your expressions against strings in real-time with highlighting
JWT Decoder
Inspect a JWT header, payload and expiry
Decode JSON Web Tokens, inspect header/payload, and check expiration
Good to know
Make the right choice before you start
01
A focused toolbox for quick development jobs
These tools are designed for the small but frequent tasks that interrupt a development workflow: checking malformed JSON, decoding an unfamiliar token, converting configuration data or making compressed code readable. Each utility opens directly to the task, with no project setup or account required.
02
Use the most specific tool for the job
Start with a dedicated formatter when you need validation and useful error feedback. Use the combined code formatter for mixed front-end snippets, the tree viewer for deeply nested JSON, and the conversion tools when the output format matters more than presentation.
Frequently asked questions
Are these developer tools safe for private code?
The core formatting, encoding and generation tools run in the browser. Always check the disclosure on an individual tool before using confidential production data.
Which tool should I use for minified JavaScript?
Use Code Beautifier & Minifier for HTML, CSS or JavaScript. Use JSON Formatter when the content is specifically JSON and needs validation.
Can I convert configuration files between formats?
Yes. The collection includes YAML and JSON conversion plus CSV, XML and JSON workflows. Review the generated result before replacing a production configuration file.
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