Epoch Converter
Convert Unix timestamps to dates and current date/time to Unix timestamps.
Developer Tools
Browser-based utilities for timestamps and developer workflows.
JSON Formatter
Format and beautify JSON with indentation, key sorting and compact mode.
JSON Minifier
Minify JSON by removing unnecessary whitespace after validation.
JSON Validator
Validate JSON and show parse errors or a formatted preview.
JSON Escape / Unescape
Escape and unescape strings for safe JSON string usage.
JSON Path Tester
Test simple JSONPath expressions against a JSON document locally.
JSON to TypeScript Interface
Generate TypeScript interfaces or types from JSON objects and arrays.
JSON to JavaScript Object
Convert strict JSON into JavaScript object literal style text.
JavaScript Object to JSON
Convert simple JavaScript-like object literals into strict JSON without eval.
HTML Entity Encoder / Decoder
Encode and decode HTML entities safely as text.
JWT Decoder
Decode JWT header and payload locally without verifying the signature.
JWT Expiration Checker
Check JWT expiration, issued-at and not-before values locally.
UUID Generator
Generate UUID v4 values locally using browser crypto.
UUID Validator
Validate UUID strings and detect UUID versions.
Hash Generator
Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes locally.
MD5 Generator
Generate legacy MD5-style checksums locally with clear non-secure labeling.
HMAC Generator
Generate HMAC signatures locally with Web Crypto.
Password Generator
Generate random passwords locally using browser crypto.
Random String Generator
Generate random strings for IDs, mock tokens and placeholders.
Lorem JSON Generator
Generate fake JSON records for testing.
Mock Data Generator
Generate local fake mock data in JSON, CSV or SQL insert text.
Regex Tester
Test JavaScript regular expressions against text locally.
Regex Escaper
Escape text so it can be used safely inside JavaScript RegExp.
Cron Expression Explainer
Explain standard 5-field cron expressions locally.
Cron Next Run Calculator
Preview upcoming cron run dates locally without scheduling jobs.
ISO Date Formatter
Inspect and format ISO/date values with browser date APIs.
URL Parser
Parse URLs into protocol, hostname, path, query, hash and params.
Query String Parser
Parse and inspect query strings and duplicate parameters.
UTM Builder
Build URLs with encoded UTM tracking parameters.
HTTP Status Code Reference
Search common HTTP status codes and developer explanations.
MIME Type Lookup
Look up common MIME types by extension or MIME string.
File Extension Lookup
Look up common file extensions, MIME types and descriptions.
HTML Formatter
Format HTML markup as text without executing scripts.
HTML Minifier
Minify HTML markup as text without fetching resources.
CSS Formatter
Format CSS code locally without fetching imports.
CSS Minifier
Minify CSS code locally without external processing.
JavaScript Formatter
Format JavaScript code as text without executing it.
JavaScript Minifier
Minify JavaScript text without evaluating code.
SQL Formatter
Format SQL query text without connecting to a database.
SQL Minifier
Minify SQL query text without execution.
XML Formatter
Format XML markup without resolving external entities.
XML Minifier
Minify XML markup as text.
YAML Formatter
Format YAML-like content locally.
YAML Validator
Validate simple YAML syntax locally and show errors.
Markdown Previewer
Generate sanitized Markdown preview HTML text locally.
Markdown Table Generator
Generate Markdown tables from columns and pasted rows.
Markdown Table Formatter
Format Markdown tables locally.
Open Graph Meta Tag Generator
Generate Open Graph meta tags as static HTML.
Twitter Card Generator
Generate Twitter/X card meta tags as static HTML.
Meta Tag Generator
Generate common SEO and HTML meta tags.
Robots.txt Generator
Generate basic robots.txt content locally.
Sitemap XML Generator
Generate sitemap XML from pasted URLs without crawling.
htaccess Redirect Generator
Generate Apache .htaccess redirect rules as text.
Nginx Redirect Generator
Generate Nginx redirect snippets as text.
Docker Run Command Generator
Generate docker run commands without executing Docker.
Docker Compose Generator
Generate simple docker-compose YAML without execution.
Environment Variable Formatter
Format .env content and detect duplicate keys locally.
ENV to JSON Converter
Convert .env key-value pairs into JSON locally.
JSON to ENV Converter
Convert flat JSON objects into .env text.
Gitignore Generator
Generate .gitignore templates from local static snippets.
License Generator
Generate common license templates locally.
README Template Generator
Generate a basic README.md template.
Changelog Generator
Generate Keep-a-Changelog style Markdown sections.
Semantic Version Comparator
Compare semantic versions locally.
Semantic Version Bumper
Calculate the next SemVer version for patch, minor or major bumps.
CORS Header Generator
Generate CORS header snippets and warnings.
CSP Header Generator
Generate basic Content Security Policy header strings.
Basic Auth Header Generator
Generate HTTP Basic Authorization headers locally.
Bearer Token Header Formatter
Format bearer tokens as Authorization headers locally.
cURL Command Builder
Build cURL commands as text without sending requests.
HTTP Request Builder
Generate raw HTTP request text without network calls.
API Error Code Mapper
Map common API and HTTP errors to likely causes and fixes.
Stack Trace Formatter
Format stack traces and extract file paths and line numbers locally.
Log Formatter
Clean and group logs locally without uploading them.
JSON Log Formatter
Format newline-delimited JSON logs and report invalid lines.
Regex Cheatsheet
Search a local JavaScript regex reference.
Git Command Cheatsheet
Search a local Git command reference without running Git.
Docker Command Cheatsheet
Search a local Docker command reference without running Docker.
About these tools
Developer utilities are built for quick checks without accounts, uploads or backend dependencies.
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