Developer Tools Guides
Step-by-step guides for developer tools. Format JSON, minify HTML/CSS/JS, encode Base64, test regex, decode JWTs, compare data formats, beautify code, and more.
Featured Developer Guides
The most popular developer tool guides to get you started quickly.
JSON Formatter
Format, validate, and minify JSON data. Fix common JSON errors, beautify minified JSON, and convert to readable formats — all in your browser.
HTML Minifier
Compress HTML files by removing whitespace, comments, and unnecessary characters. Reduce file sizes and improve page load speeds for production.
JWT Decoder
Decode JWT tokens instantly to inspect headers, payloads, and signatures. Debug authentication issues with fully local, private token inspection.
Base64 Encoder
Encode text and files to Base64 format, or decode Base64 strings back to plain text. Perfect for data URI creation and email attachments.
Regex Tester
Test regular expressions with real-time matching, highlighting, and capture groups. Debug and refine your patterns before using them in code.
JSON Compare
Compare two JSON objects side by side and highlight differences. Identify added, removed, or changed values in nested structures instantly.
All Developer Tool Guides
Browse our complete collection of developer tool tutorials organized by category.
JSON Formatter
Format, validate, and minify JSON data.
XML Formatter
Format and validate XML documents with indentation.
HTML Minifier
Compress HTML files by removing whitespace and comments.
CSS Minifier
Minify CSS files to reduce load times.
JavaScript Minifier
Compress JavaScript files for production.
HTML Encoder
Encode and decode HTML entities safely.
Base64 Encoder
Encode and decode Base64 strings and files.
URL Encoder
Encode and decode URLs for safe transmission.
Regex Tester
Test regular expressions with real-time matching and highlighting.
JWT Decoder
Decode JWT tokens and inspect headers and payloads.
JWT Generator
Build and generate JWT tokens for development.
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes.
Hash Checker
Verify data integrity with hash comparison.
JSON Compare
Compare two JSON objects and highlight differences.
JSON Escape / Unescape
Escape and unescape JSON strings with special characters.
JSON to YAML
Convert JSON data to YAML format.
YAML to JSON
Convert YAML files to JSON format.
JSON to CSV
Convert JSON data to CSV spreadsheet format.
CSV to JSON
Convert CSV files to structured JSON format.
XML to JSON
Convert XML documents to JSON format.
HTML Beautifier
Format and indent HTML code for readability.
HTML Validator
Validate HTML markup and find errors.
CSS Beautifier
Format and beautify CSS code with proper indentation.
JavaScript Beautifier
Format and beautify JavaScript code for readability.
URL Parser
Parse URLs into components: protocol, host, path, and more.
Query String Parser
Parse and decode URL query string parameters.
HTTP Status Lookup
Look up HTTP status codes and their descriptions.
MIME Type Lookup
Look up MIME types for file extensions and vice versa.
UUID Validator
Validate UUID strings and check their version and format.
Frequently Asked Questions
How do I format or validate JSON data?
Use the JSON Formatter tool. Paste your JSON string and the tool instantly validates, formats with indentation, or minifies it. You can also fix common JSON errors like trailing commas and missing quotes.
Can I minify HTML, CSS, and JavaScript without losing functionality?
Yes. The HTML, CSS, and JavaScript Minifier tools remove whitespace, comments, and unnecessary characters without affecting functionality. This reduces file sizes and improves page load speeds.
How do I encode and decode Base64 strings?
Use the Base64 Encoder tool to encode text or files into Base64 format, and decode Base64 back to plain text. All encoding and decoding happens locally in your browser — nothing is uploaded.
What is JWT and how do I decode a token?
JWT (JSON Web Token) is a compact token format used for authentication. Use the JWT Decoder to paste your token and instantly see the decoded header, payload, and signature — all processed locally.
Can I convert between JSON, YAML, XML, and CSV formats?
Yes. GoToolly offers converters between all major data formats: JSON to YAML, YAML to JSON, JSON to CSV, CSV to JSON, and XML to JSON. All conversions happen in your browser with no data uploads.
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PDF Guides
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Image Guides
Compress, resize, convert, crop, and optimize images with detailed visual guides.
Text & Writing Guides
Word counters, text diff, readability checkers, and text transformation tools.
Utility Guides
Generators, calculators, converters, and everyday utility tools explained step by step.