Free Developer Tools: JSON, JWT, Regex & SEO
Inspect data, debug formats and prepare code without setting up a project. Format JSON before converting it to TypeScript, inspect token payloads, test a regular expression or preview a search snippet.
JWT Decoder
Decode JSON Web Tokens securely in your browser
JWT Encoder
Create and sign JSON Web Tokens with custom payloads
JSON Formatter
Format, validate, and beautify JSON data
Regex Tester
Test and debug regular expressions in real-time
Diff Checker
Compare two texts and highlight the differences
Markdown Preview
Write and preview Markdown in real-time
Meta Tag Generator
Generate complete meta tags for SEO and social previews.
Website Speed Test
Check loading speed and core performance metrics for any URL.
Keyword Density Checker
Check keyword density to optimize your content for search engines
SERP Snippet Preview
Preview Google result snippets and validate title/meta description length.
Robots.txt Generator
Generate robots.txt rules to control crawling and include sitemap directives.
Canonical URL Checker
Validate canonical URLs and catch common indexing mistakes.
Hreflang Generator
Create hreflang tags for multilingual SEO and validate locale mappings.
CSS Minifier
Minify and compress CSS code to reduce file size
JavaScript Minifier
Minify JavaScript code for production
HTML Minifier
Compress HTML markup by removing whitespace
SQL Formatter
Format and beautify SQL queries
XML Formatter
Format and validate XML documents
Chmod Calculator
Calculate Unix file permissions
Open Graph Preview
Preview how your page looks on social media
Twitter Card Preview
Preview Twitter card metadata
UTM Link Builder
Build UTM tracking parameters for campaigns
Schema Markup Generator
Generate JSON-LD structured data for SEO
FAQ Schema Generator
Create FAQ schema markup for rich snippets
Chmod Converter
Chmod Converter - Free online tool
Choose by the task you need to finish
- Validate JSON before generating TypeScript interfaces from the same sample.
- Use the JWT decoder to inspect claims; decoding alone does not verify a signature.
- Preview a page title and description before publishing; search engines may rewrite the displayed snippet.