Regex Lab
Test JavaScript regular expressions with offsets, groups, indices, replacements, expected cases, token explanations, and heuristic ReDoS warnings.
Private browser workbench
KAZCODE DevBench
A privacy-first browser toolbox for JavaScript regex testing, everyday conversions, validation, decoding, hashing, and text comparison.
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Static files. Local transformations. No third-party runtime assets.
Data
JSON Formatter And Validator
Format, minify, and validate JSON with parser errors rendered as text.
Text
Regex Lab
Test JavaScript RegExp patterns locally with worker timeouts, offsets, groups, replacements, cases, explanations, and heuristic ReDoS warnings.
Uses browser JavaScript RegExp semantics. Execution runs in a dedicated Worker and is terminated if it exceeds the timeout.
Advanced Regex options
Data
JWT Decoder
Decode header and payload locally. Signatures are NOT verified.
Decoded locally. Signature is not verified and this tool does not validate trust or token safety.
Encoding
Base64 Encoder And Decoder
Encode and decode UTF-8 text. Whitespace in Base64 input is ignored.
Base64 is encoding, not encryption.
Encoding
URL Component Encoder And Decoder
Encode or decode URI components without navigating to user-provided URLs.
Time and IDs
Unix Timestamp Converter
Choose seconds or milliseconds explicitly, then convert to local and ISO time.
Time and IDs
UUID v4 Generator
Generate canonical lowercase UUID v4 identifiers using secure browser crypto.
Crypto
SHA-256 Hash Generator
Hash UTF-8 text locally with Web Crypto and return lowercase hexadecimal.
SHA-256 is a hash, not encryption. Plain SHA-256 is not password storage.
Text
Text Diff
Compare two text blocks line by line. User text is rendered literally, never as markup.
Developer Tools That Stay In Your Browser
KAZCODE DevBench gives developers a worker-protected JavaScript Regex Lab plus common encoding, validation, timestamp, hash, JWT, UUID, and text comparison tools that run entirely in the browser.
Tools Included
JSON Formatter and Validator
Format, minify, and validate JSON with inline errors.
JWT Decoder
Decode header and payload locally; no signature verification.
Base64 Encoder and Decoder
Encode and decode UTF-8 text.
URL Encoder and Decoder
Encode and decode URI components.
Unix Timestamp Converter
Convert seconds or milliseconds to local and ISO time.
UUID Generator
Generate UUID v4 values using secure browser crypto.
SHA-256 Hash Generator
Hash text locally with lowercase hexadecimal output.
Text Diff
Compare text line by line with added, removed, and unchanged rows.
Privacy And Local Processing
DevBench is a dependency-free static page. Tool inputs live only in the current page controls, are not stored after refresh, and are not sent to KAZCODE or third parties.
Frequently Asked Questions
How does Regex Lab avoid freezing the page?
Regex Lab runs JavaScript regular expressions in a dedicated browser Worker with a hard timeout. If a pattern takes too long, the Worker is terminated and the page stays responsive.
Does Regex Lab use the same behavior as my browser JavaScript?
Yes. It uses the browser's built-in RegExp engine, including the supported flags and the d indices flag when that browser supports it.
Does KAZCODE DevBench send my data to a server?
No. The tools run in your browser and are designed without telemetry, remote processing, or saved tool inputs.
Can DevBench verify JWT signatures?
No. The JWT tool decodes the header and payload only. It does not verify signatures, validate trust, or prove that a token is safe.
Is Base64 encryption?
No. Base64 is an encoding format, not encryption. Anyone can decode Base64 text.
Can I use SHA-256 here for passwords?
DevBench can calculate a SHA-256 hash of text, but plain SHA-256 is not a password storage scheme. Production password storage needs a dedicated password hashing algorithm and salts.
Does DevBench work offline?
After the static files are loaded, the tools do not require server processing. If offline support is added later, it must be implemented without caching user input.
What tools are included?
Regex Lab, JSON formatter/validator, JWT decoder, Base64 encoder/decoder, URL encoder/decoder, UUID v4 generator, Unix timestamp converter, SHA-256 hash generator, and text diff.