JSON Formatter
Format, minify, and validate JSON.
Paste an API response, log line, config value, or webhook body. The formatter makes valid JSON readable and reports parsing errors for invalid text.
Read the JSON tutorialReady.
Private by design
Developer tools that run in your browser.
Format, encode, compare, inspect, and generate common developer data without sending your text to our server. DevUtils.uk is for quick everyday checks, not account tracking or file collection.
No sign-inLocal processingOriginal tutorials
{
"site": "DevUtils.uk",
"processing": "browser-only",
"tools": 10
}
Site explanation
Who built this and what is it for?
DevUtils.uk is maintained as an independent utility site for developers, QA testers, technical support teams, writers, and students. The tools below are implemented with client-side JavaScript. Normal tool input is processed in your browser tab and is not uploaded to a DevUtils.uk server.
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One clearly labeled ad area, separated from tools and navigation.
Tools
Choose a utility
Each tool has a short workflow here and a longer tutorial with examples and common mistakes.
Base64 Encoder / Decoder
Encode text or decode readable payloads.
Use Base64 for small test strings, headers, or diagnostic payloads. It is encoding, not encryption, so do not treat it as a security layer.
Read the Base64 tutorialReady.
URL Encoder / Decoder
Prepare query values and inspect escaped URLs.
Encode text before placing it inside a URL parameter, or decode copied links to see the actual value behind percent escapes.
Read the URL tutorialReady.
UUID Generator
Create random UUID v4 identifiers.
Generate IDs for fixtures, test records, local databases, API examples, and demo payloads. IDs are generated by browser crypto when available.
Read the UUID tutorialReady.
Timestamp Converter
Convert Unix time, milliseconds, and ISO dates.
Debug logs, database fields, scheduled jobs, and API responses by converting machine timestamps into readable dates.
Read the timestamp tutorialReady.
SHA-256 Hash
Create a digest for text.
Use SHA-256 to compare text integrity, create deterministic examples, or document exactly which string was used in a bug report.
Read the hash tutorialReady.
Color Converter
Convert hex to RGB and HSL.
Paste a hex value to get CSS-ready RGB and HSL values. The preview swatch helps confirm the copied color is the intended one.
Read the color tutorialReady.
Text Diff
Compare two short snippets line by line.
Paste an old and new value to find changed, added, or removed lines before sending a config update or support response.
Read the diff tutorialReady.
Regex Tester
Test JavaScript regular expressions.
Check whether a pattern matches sample text before adding it to validation code, log filters, or search scripts.
Read the regex tutorialReady.
JWT Inspector
Decode JWT headers and payloads without verification.
Inspect token claims while remembering that this browser tool does not validate signatures, issuers, audiences, or expiry policy.
Read the JWT tutorialReady.