Free Developer Tool Widgets for Docs and Blogs
JSON, Base64, URL, JWT, UUID, timestamp, regex and cron widgets for documentation, tutorials and internal wikis. Input never leaves the browser.
Try them live
Real developer tools widgets - exactly what your visitors would see.
The live example loads when it scrolls into view.
Who these are for
Documentation writers, API providers, tutorial authors and internal wikis.
Common uses
- Beside API docs so readers can decode a sample JWT or format a JSON response
- In a cron or regex tutorial where readers try their own pattern
- On an internal wiki page for timestamp and UUID look-ups
How embedding works
Pick a widget, set the theme and size, copy one line of HTML and paste it into your page. It runs in its own frame, so it cannot clash with your site's styles, and it resizes itself if you use the loader.
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Pretty-print, minify or validate JSON, with the line and column of the first syntax error.
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Convert a JSON array of objects to CSV and CSV back to JSON, with RFC 4180 quoting.
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Encode text to Base64 or decode it, with proper UTF-8 and an optional URL-safe alphabet.
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Percent-encode or decode text and URLs, and find the exact position of a malformed escape.
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Read a JSON Web Token's header and claims, with exp, nbf and iat shown as dates.
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Generate 1 to 100 random v4 or time-ordered v7 UUIDs in several formats.
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Live epoch time, timestamp to date (seconds to nanoseconds detected) and date to timestamp.
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Test a JavaScript regular expression: highlighted matches, capture groups and a replace preview.
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Turn a cron schedule into plain English and list its next five run times.
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MD5, SHA-1, SHA-256, SHA-384 and SHA-512 of any text, in hex or Base64.
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Live Markdown preview with tables and task lists, plus safe HTML to copy.
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Network, broadcast, host range, masks and host count for any IPv4 CIDR, with subnet splitting.
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Cost per request, day and month for any LLM API from tokens or words and your own prices.
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Estimated GPU memory to run a language model: weights by precision plus KV cache and overhead.
No widget matches that search.
Other widget categories
- All calculators
- Finance
- Real Estate
- Business & Ecommerce
- Marketing
- SEO & Content
- Website & Security
- Electrical & Electronics
- Education & Math
- Time & Date
- Travel & Auto
- Health & Fitness
- Design
- QR & Generators
- Construction & DIY
- Solar & Energy
- HVAC & Climate
- Logistics & Shipping
- Manufacturing & Operations
- SaaS & Startups
- HR & Work
- Creators & Media
- Food & Restaurant
- Events & Weddings
- Pets
- Agriculture & Garden
- Networking & IT
- Business & Contact
- Announcements & Notices
- Page Components
How to add a widget
Open a widget, choose the theme, width and style, check the live preview, then copy the code. Paste it into an HTML or "Custom code" block on your site - step-by-step instructions for each platform.