Static, local-first utilities by Lumarc Studio
Free Developer Tools That Run in Your Browser
Format, convert, validate and generate developer data without uploading it to a server.
Start with the tools developers reach for most
Fast utilities for API payloads, encoded values, generated identifiers and timestamp debugging.
JSON Formatter
Beautify JSON and validate syntax with readable indentation and precise parse errors.
JSON Tools ✓JSON Validator
Check whether JSON is valid and see clear syntax errors before using it in code.
JSON Tools 64Base64 Encoder
Encode Unicode text as Base64 for transport in configuration, headers and scripts.
Encoding Tools AaBase64 Decoder
Decode Base64 text back to UTF-8 so encoded payloads are easy to inspect.
Encoding Tools #UUID Generator
Generate RFC 4122 version 4 UUIDs locally using the browser crypto API.
Generator Tools ••Secure Password Generator
Generate strong random passwords locally with browser cryptography.
Generator Tools ⏱Unix Timestamp Converter
Convert Unix timestamps to human-readable UTC and local dates, or convert dates back to Unix time.
Date and Time Tools YJSON to YAML Converter
Convert valid JSON into readable YAML for configuration files and documentation.
Converter Tools JYAML to JSON Converter
Convert YAML documents into formatted JSON with clear parse errors.
Converter Tools CSVJSON to CSV Converter
Convert arrays of JSON objects into CSV for spreadsheets, QA checks and exports.
Converter Tools []CSV to JSON Converter
Convert CSV text with headers into formatted JSON arrays.
Converter Tools JWTJWT Decoder
Decode JWT header and payload JSON locally without claiming signature verification.
Security ToolsPopular local tools
Every interaction runs in the browser. Paste data, process it, copy the result, move on.
JSON Formatter
Beautify JSON and validate syntax with readable indentation and precise parse errors.
JSON Tools ✓JSON Validator
Check whether JSON is valid and see clear syntax errors before using it in code.
JSON Tools ⇥JSON Minifier
Remove whitespace from valid JSON to create compact payloads and fixtures.
JSON Tools 64Base64 Encoder
Encode Unicode text as Base64 for transport in configuration, headers and scripts.
Encoding Tools AaBase64 Decoder
Decode Base64 text back to UTF-8 so encoded payloads are easy to inspect.
Encoding Tools %URL Encoder
Percent-encode text for safe use in URLs, query strings and redirect parameters.
Encoding Tools /URL Decoder
Decode percent-encoded URL text into readable characters.
Encoding Tools #UUID Generator
Generate RFC 4122 version 4 UUIDs locally using the browser crypto API.
Generator ToolsBrowse by category
Published clusters are indexable when they contain useful tools; future clusters stay out of search until they are ready.
JSON Tools
Format, validate and minify JSON in your browser with clear errors and private local processing.
3 toolsEncoding Tools
Encode and decode Base64, URLs and other transport-safe formats without sending values to a server.
7 toolsGenerator Tools
Generate UUIDs, secure passwords and other developer-ready values locally in your browser.
2 toolsDate and Time Tools
Convert Unix timestamps and inspect date values across UTC and local time for debugging and logs.
1 toolsText Tools
Clean, compare and transform plain text.
1 toolsFormatter Tools
Readable formatting tools for structured data.
0 toolsConverter Tools
Convert data between common developer formats.
4 toolsSecurity Tools
Security-oriented helpers that keep sensitive input local.
2 toolsWeb Tools
Utilities for web platform debugging and delivery.
0 toolsCSS Tools
CSS inspection, conversion and generation helpers.
0 toolsJavaScript Tools
JavaScript and runtime debugging utilities.
0 toolsData Tools
Data conversion and inspection tools for technical workflows.
0 toolsImage Tools
Browser-based image inspection and conversion utilities.
0 toolsSEO Tools
Technical SEO checks and structured data helpers.
0 toolsQA Tools
Testing and QA utilities for repeatable checks.
0 toolsPrivate by default
Lumarc DevTools is built as a static site. Tool input is processed by browser APIs on your device, with no backend, account system or analytics script in the initial implementation.