JWT Decoder
Decode the header and payload of a JWT without the token ever leaving your browser.
Free tools for developers and SEOs
Every DevSEOCraft tool in one place. All of them run in your browser, need no signup, and never send what you paste to a server.
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Developer tools
11.env Validator
Catch quoting, duplicate and syntax bugs in a .env file before they break your deploy.
Cron Expression Parser
Translate a cron expression into plain English and see exactly when it runs next.
UUID Generator
Generate cryptographically random UUID v4 or time-ordered UUID v7, in bulk.
Base64 Encoder & Decoder
Encode and decode Base64 with correct UTF-8 handling, including the URL-safe alphabet.
Unix Timestamp Converter
Convert epoch timestamps to readable dates and back, with automatic unit detection.
SHA Hash Generator
Compute SHA-1, SHA-256, SHA-384 and SHA-512 digests of any text, in your browser.
JSON to YAML Converter
Convert JSON to YAML and back, with real duplicate-key detection instead of a silent overwrite.
Case Converter
Convert text between camelCase, PascalCase, snake_case, kebab-case and more, all at once.
Password Generator
Generate a random password with Web Crypto, and see exactly how strong it actually is.
Text Diff Checker
Compare two blocks of text line by line and see exactly what changed.
SEO tools
04SERP Snippet Preview
See how your title and meta description will be truncated in Google, measured in pixels.
UTM Builder
Build campaign URLs that GA4 actually attributes, with the mistakes flagged as you type.
URL Slug Generator
Turn any headline into a clean, ASCII-safe URL slug, accents and symbols included.
FAQ Schema Generator
Turn a list of questions and answers into valid FAQPage JSON-LD, checked against Google's rules.