Popular Developer Utilities
The most frequently used tools on Lab Tool, compiled from monthly execution counts and user bookmark rates. Run them instantly, 100% locally.
JSON Formatter & Validator
Format, validate, beautify, and inspect JSON payloads with custom indentation and tree view.
Regex Tester & Debugger
Test Javascript regular expression matches, capture groups, and replacements in real time.
REST API Request Builder
Build, test, debug and inspect REST APIs, GraphQL APIs and HTTP requests.
UUID / ULID Generator
Generate bulk RFC 4122 v4 UUIDs or time-sortable ULIDs with custom formatting options.
Base64 Encoder / Decoder
Encode plain text or binary strings into Base64 format or decode back to UTF-8 text.
Hash Generator (MD5, SHA-256, SHA-512)
Generate cryptographic checksums and hash signatures for texts and file strings.
Text & Code Diff Checker
Compare two text snippets or code blocks side-by-side to highlight added or removed lines.
JSON → CSV Converter
Transform structured JSON arrays or nested objects into RFC 4180 compliant CSV format.
SVG Formatter & Beautifier
Validate and format SVG markup into clean, readable XML.
Password & Secret Key Generator
Create high-entropy passwords with custom character sets and password strength analytics.
SEO URL Slug Sanitizer
Convert titles, strings, and headlines into SEO-friendly clean URL slugs.
SQL Formatter & Beautifier
Beautify MySQL, MariaDB, PostgreSQL, SQLite, and ANSI SQL queries with customizable spacing and case formatting.
SVG Minifier
Remove metadata and redundant whitespace from SVG markup.
Cron Expression Parser & Humanizer
Parse 5-part cron syntax expressions into human-readable schedules with upcoming run times.
cURL Command Builder
Build production-ready cURL commands with URL, method, headers, and body.
JSON Minifier
Compress JSON objects by stripping whitespaces and line breaks for minimum payload size.
SVG Data URI Encoder
Convert SVG markup into a compact CSS-ready data URI.
CSV → JSON Converter
Parse CSV spreadsheets into structured JSON arrays with automatic type detection.
JavaScript Fetch Code Generator
Generate JavaScript Fetch API code templates for HTTP requests.
Markdown Live Editor & Preview
Write GFM Markdown with real-time rendered preview, table formatting, and HTML exporting.
LLM Token Counter (Estimate)
Estimate how many tokens a prompt will use across common LLM tokenizers.
robots.txt & Sitemap Generator
Configure web crawler access rules, user agents, allow/disallow directives, and sitemap URLs.
SVG Open Graph Image Generator
Generate a branded 1200 by 630 social sharing image as editable SVG.
YAML → JSON Converter
Convert YAML (mappings, sequences, nesting, comments) into JSON. Invalid indentation is reported honestly.
Dockerfile Generator & Linter
Validate Dockerfile best practices, layer size optimization, and multi-stage build tips.
HTTP Header Inspector
Analyze request headers, response headers, security headers, CORS, and Cache rules.
JSON → TypeScript Interface
Generate TypeScript interfaces from a JSON sample with inferred types.
MySQL → JSON Dumper
Convert MySQL dump schema statements or table rows into structured JSON tables.
SVG Data URI Decoder
Decode URL-encoded or Base64 SVG data URIs into editable markup.
Timezone Converter
Convert a date and time from one IANA timezone to another.
Axios Request Generator
Generate production-ready Axios configurations and request snippets.
JSON Diff Checker
Deep-compare two JSON objects and list every added, removed, and changed key.
JWT Token Decoder & Inspector
Decode and inspect JSON Web Tokens (JWT) payload, header, signature structure, and verify token signatures locally.
SVG Dimensions & ViewBox Inspector
Inspect width, height, viewBox and SVG element counts.
XML → JSON Converter
Convert XML into structured JSON. Attributes become @-prefixed keys; repeated elements become arrays.
JSON → YAML Converter
Convert JSON into clean, human-readable YAML with correct quoting of ambiguous scalars.
SVG Color Replacer
Replace fill and stroke colors throughout SVG markup.
Webhook Request Tester
Send, receive, replay, and inspect webhook requests in your browser sandbox.
.env to JSON Converter
Parse dotenv-style KEY=VALUE files into a structured JSON object.
Shopify Product CSV Validator
High-throughput offline verification of Shopify catalog feeds. Audits columns, handles images, handles variant prices, and logs anomalies.
SVG CSS Background Generator
Generate reusable CSS background-image code from SVG markup.
Unix Timestamp Converter
Convert between Unix timestamps and human-readable UTC dates.
XML Formatter & Beautifier
Validate, indent, and beautify XML documents. Malformed markup is reported, never silently reshaped.
IPv4 Subnet Calculator
Compute network address, broadcast, usable host range, and mask from CIDR notation.
SVG Placeholder Generator
Generate responsive image placeholders with custom dimensions and text.
URL Encoder / Decoder
Percent-encode or decode text for safe use in URLs and query strings.
GraphQL Query Builder
Construct, validate, format, and run GraphQL queries and mutations.
SVG Favicon Generator
Create a scalable favicon from initials and brand colors.
PBKDF2 Key Derivation Generator
Derive a PBKDF2 key from a password and salt using the browser's native Web Crypto API.
String Case Converter
Convert an identifier or phrase into camelCase, snake_case, kebab-case, PascalCase and more.
Color Converter (HEX / RGB / HSL)
Convert a color between HEX, RGB, and HSL notations.
Color Shades & Tints Generator
Generate a palette of tints and shades from a single base hex color.
JWT Generator (HS256)
Sign a JSON payload into a HS256 JWT with your secret. Runs entirely in your browser.
YAML Linter & Validator
Check YAML for structural validity and report the parsed shape, or the exact line that fails.
Word & Character Counter
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CSS Unit Converter
Convert CSS length values between px, rem, em, pt, and percent.
HTML Entity Encoder / Decoder
Escape or unescape HTML entities so markup renders as text (and back).
Password Strength Checker
Estimate password entropy and strength from its length and character set.
HTTP Status Code Explorer
Search and inspect HTTP response status codes: 200, 201, 301, 401, 403, 404, 500 etc.
Meta Tag & Open Graph Generator
Generate SEO, Open Graph, and Twitter Card meta tags for a page.