Developer Tools
Developers constantly switch between small utilities: formatting a JSON payload, testing a regex, decoding a JWT, cleaning up a long SQL query. These tools handle that work locally in your browser — your code and data are not sent to a server, which matters when you are debugging something sensitive.
15 developer utilities available
What can you do with developer tools?
Format and validate JSON
Beautify minified JSON and catch syntax errors — trailing commas, missing quotes, mismatched brackets.
Work with patterns
Generate regex patterns for common cases and format SQL into readable, maintainable queries.
Inspect tokens and config
Decode JWT headers and payloads to debug authentication, and validate YAML syntax for configuration files.
Preview and generate
Preview Markdown as rendered HTML, generate UUIDs and secure passwords, and check code and cron expressions.
Which developer tool should you use?
Pick the task, then use the matching tool.
| I want to… | Use |
|---|---|
| Format or validate JSON | JSON Formatter |
| Generate a regex pattern | Regex Generator |
| Format a SQL query | SQL Formatter |
| Decode a JWT token | JWT Decoder |
| Validate YAML | YAML Validator |
| Preview Markdown | Markdown Preview |
| Encode/decode Base64 | Base64 Encoder |
| Generate UUIDs | UUID Generator |
Featured developer tools
JSON Formatter
Format, validate, and inspect JSON instantly. Essential for debugging API responses and configuration files.
Regex Generator
NewGenerate a ready-to-use regex for common cases such as email or URL matching.
SQL Formatter
NewFormat and beautify standard ANSI SQL queries (SELECT, JOIN, WHERE, GROUP BY, ORDER BY, CTEs, subqueries) with clean keyword indentation.
JWT Decoder
NewDecode JSON Web Tokens and inspect the header and payload contents.
YAML Syntax Checker
NewCheck YAML indentation, syntax, forbidden tabs, and unclosed quotes directly in your browser before parsing.
Markdown Preview
NewPreview how your Markdown content will render as HTML with live conversion.
Base64 Encoder
Encode and decode Base64 strings with validation. Useful for embedding binary data in JSON or HTML.
UUID Generator
Generate random UUIDs for applications and databases. Create unique identifiers for database records, API requests, and distributed systems.
Code Explainer
NewGet a structural overview of a code snippet — line count and function count. Runs locally in your browser.
Dockerfile Generator
NewGenerate Dockerfile configurations for various application types and runtimes.
API Tester
NewGenerate curl commands and API test requests for common HTTP methods and endpoints.
Cron Expression Generator
NewGenerate a cron expression from a simple schedule such as daily or hourly.
Git Ignore Generator
NewGenerate .gitignore files for your tech stack and development environment.
Hash Generator
NewCalculate SHA-1, SHA-256, SHA-384, and SHA-512 cryptographic hashes using the native Web Crypto API, plus MD5 via a fast client-side algorithm for legacy checksums.
Unix Timestamp Converter
NewConvert Unix timestamps to human-readable dates and parse date strings into epoch timestamps.
Developer guides
Learn the concepts behind the tasks before (or after) you run the tools.
Developer
JSON Formatting and Validation: A Developer's Guide to Clean Data
Master JSON formatting, validation, and debugging with practical examples and best practices.
Developer
Regex Tutorial: Patterns for Real-World Matching
A beginner-friendly guide to regular expressions — literals, character classes, quantifiers, groups, and the mistakes to avoid.
Developer
JWT Explained: What a JSON Web Token Actually Is
Header, payload, signature — and why decoding a JWT is not the same as verifying it. A security-accurate explainer.
Developer
SQL Formatting Best Practices: Readable Queries That Scale
Consistent indentation, capitalized keywords, clear aliases — the formatting habits that make SQL maintainable.
Developer
YAML Guide: Syntax, Common Errors, and When to Use It
Indentation, mappings, arrays, and the YAML gotchas that break config files — plus how YAML compares to JSON.
Developer
Markdown Cheat Sheet: Everything You Need to Write Better Docs
Headers, lists, tables, code blocks, and links — the only Markdown guide you will need for READMEs and docs.
Security
Why Browser-Based Tools Are the Safest Way to Handle Sensitive Documents
Discover why processing files in your browser protects privacy better than desktop or cloud alternatives.
Frequently asked questions
Is my code or data sent to a server?
No. These developer tools run entirely in your browser — JSON, regex, SQL, JWT, YAML, and Markdown are all processed locally. Nothing you paste is transmitted or stored.
Does decoding a JWT verify its signature?
No. Decoding simply reads the header and payload; verifying a token's signature requires the signing key. Never trust a token's contents based on decoding alone.
Can I validate JSON with comments?
No. Standard JSON does not support comments. The JSON Formatter will flag them as invalid — consider YAML if you need comments in configuration.
Are these tools safe for sensitive data?
Yes. Because processing happens locally, pasting API responses, tokens, or configuration into these tools does not send that data anywhere.
Do I need to install anything?
No. Every current tool runs in the browser with no installation and no account. Practical limits come from browser memory and file size rather than from a server.