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Developer Tools
273 appsDeveloper Tools: Common Formats
Date Regex Sample Generator
Generate ISO-shaped date strings for parser and form tests, then check real calendar rules separately.
Email Regex Sample Generator
Generate example email addresses on reserved example and test domains.
Filename Regex Sample Generator
Generate lowercase file names with common test extensions and no folder paths.
Hex Color Regex Sample Generator
Generate uppercase six-digit hexadecimal colors for design and form tests.
IPv4 Regex Sample Generator
Generate IPv4 values whose four number parts stay between 0 and 255.
Order Number Regex Sample Generator
Generate order-number examples for receipt, search, and import testing.
Phone Regex Sample Generator
Generate North American phone-shaped examples for formatting and input tests.
SKU Regex Sample Generator
Generate product SKU examples with letters, digits, and fixed separators.
Tracking Code Regex Sample Generator
Generate fake tracking-shaped codes without using a real carrier number.
URL Slug Regex Sample Generator
Generate lowercase, hyphen-separated slug values for route and form testing.
Username Regex Sample Generator
Generate lowercase usernames that follow a clear length and character rule.
Developer Tools: CSS & JavaScript
CSS Declaration Explorer
Search CSS property names and values, find important declarations, and export their locations for stylesheet cleanup.
CSS Prefix Preview
Add vendor prefixes for browsers you choose. See resolved browser versions and download the resulting CSS and source map.
CSS Rule Inventory
Count CSS rules, selectors, properties, and at-rules. See repeated values and download a complete stylesheet inventory.
CSS Syntax Validator
Check CSS syntax, find errors by line and column, and explore a structured tree without applying the styles to your page.
CSS Transformation Playground
Flatten nested CSS, add browser prefixes, and remove comments with a before-and-after view and downloadable CSS.
JavaScript Minifier
Make JavaScript smaller with controls for compression, variable names, and comments. Download the code and an optional source map.
Legacy CSS Compatibility Diff
Compare CSS before and after browser-prefix changes. Inspect added and removed declarations for your chosen browser targets.
Minification Impact Viewer
Compare original, minified, and formatted JavaScript. Measure UTF-8 and gzip sizes, then download code and source maps.
Developer Tools: Developer Utilities
Barcode Check Digit Calculator
Calculate or verify the GS1 check digit for GTIN-8, UPC-A, EAN-13, GTIN-14, and SSCC-18 codes.
Barcode CSV Auditor
Check a CSV column of product barcodes for invalid lengths, non-digit characters, and incorrect check digits.
Domain Character Inspector
Check the exact characters in a domain name. See Unicode codes and decoded Punycode to spot lookalike letters.
Glob Pattern Tester
Test a file glob against a list of paths. See which filenames match your pattern before using it in a script.
HTML Entity Decoder
Decode named and numeric HTML entities into plain text without rendering the result as HTML.
HTML Entity Encoder
Convert text to HTML entities. Escape symbols such as < and & so they can appear as text in HTML code.
IDN / Punycode Converter
Convert international domain names between Unicode and Punycode. Compare readable names with their xn-- form.
Semantic Version Range Checker
Check which package versions fit an npm version range. Test rules such as ^1.2.3 against a list of versions.
Unicode Entity Explorer
Inspect Unicode characters one by one. See each character's number, UTF-8 bytes and HTML entity code.
Developer Tools: Document & Data Services
Developer Tools: Explore a Pattern
Long Regex Sample Finder
Generate many matches and keep the longest examples found in that sample run.
Regex Coverage Pack Maker
Make a small test pack that covers several lengths and removes duplicate strings.
Regex Sample Length Explorer
Generate a test batch and compare its shortest, longest, and average string lengths.
Short Regex Sample Finder
Generate many matches and keep the shortest examples found in that sample run.
Developer Tools: Filter & Reshape
JSON Array Filter
Filter a JSON array with a clear JSONata condition and keep the matching objects.
JSON Array Flattener
Pull values from arrays inside records into one simple result sequence.
JSON Array Grouper
Group array records by a field and return one object with a key for each group.
JSON Array Sorter
Sort an array by text or numbers with JSONata's order-by operator.
JSON Field Picker
Turn each object into a smaller object with a chosen set of fields.
JSON Field Renamer
Build new objects with renamed fields while keeping the original JSON unchanged.
JSON Object Reshaper
Combine fields, filters, and nested results into a cleaner object for another system.
Developer Tools: Find Code Parts
JavaScript Arrow Function Finder
List arrow functions with inferred names, parameters, async state, and source lines.
JavaScript Async Function Finder
Find async declarations, expressions, and arrows with names, parameters, and lines.
JavaScript Await Expression Finder
List awaited expressions with their readable source text and exact line.
JavaScript Call Expression Finder
List function and method calls with readable callee names, argument counts, and lines.
JavaScript Class Inventory
List class declarations and expressions with inheritance and method counts.
JavaScript Comment Extractor
Extract comments with their type, text, line, and character count.
JavaScript Dynamic Import Finder
List dynamic import expressions, source values, and exact locations.
JavaScript Event Listener Finder
List event listener calls, target expressions, event names, and lines.
JavaScript Export Inventory
Find export statements, names, source modules, lines, and export kinds.
JavaScript Function Inventory
Find function declarations and expressions with names, parameters, lines, and flags.
JavaScript Import Inventory
Find static imports, source packages, local names, and import kinds.
JavaScript Number Literal Extractor
Extract decimal, hex, binary, octal, bigint, and exponent number literals.
JavaScript Object Key Finder
Find object property keys, method keys, computed state, and source lines.
JavaScript Optional Chaining Finder
List optional member and call expressions with their source lines.
JavaScript String Literal Extractor
Extract string and template text with quote type, length, and source line.
JavaScript Variable Declaration Finder
Find declared names, declaration kinds, initial values, lines, and nesting depth.
Developer Tools: Generate Samples
Bulk Regex Sample Generator
Generate up to 250 matching strings for forms, imports, and test fixtures.
Regex Example Generator
Enter a regular expression and make clear example strings that match it.
Seeded Regex Sample Generator
Use a seed so the same pattern and settings make the same strings again.
Unique Regex Sample Generator
Try extra generations and keep only distinct strings that match your pattern.
Developer Tools: IDs & Codes
Random Invite Code Batcher
Create unique offline invitation codes with a readable alphabet and optional event prefix, then download the full batch.
Record ID Migration Mapper
Map old record IDs to fresh UUID v4 or v7 values, review repeated IDs, and export a complete local lookup table.
Short Identifier Generator
Generate random short IDs using your chosen alphabet, length and prefix, then export a batch as CSV, JSON or text.
Developer Tools: Inspect & Validate
Liquid Filter Inventory
Find Liquid filter names, counts, and source lines without rendering the output.
Liquid Output Escaping Checker
List output expressions and confirm that Bookify's preview applies default HTML escaping.
Liquid Syntax Checker
Parse a Liquid template with strict filters and show a clear local syntax result.
Liquid Tag Inventory
List if, for, assign, capture, case, and other Liquid tags with line numbers.
Liquid Variable Finder
Find root variables and full nested paths without rendering the template.
Developer Tools: JSON Web Keys
JWK Key Pair Generator
Generate an RS256 or ES256 JWK pair and a stable key ID in your browser.
JWK Thumbprint Calculator
Calculate the RFC 7638 SHA-256 thumbprint and thumbprint URI for a JWK.
JWK to PEM Converter
Convert an RSA or EC JWK into a public SPKI or private PKCS8 PEM key.
JWKS Inspector
List key IDs, algorithms, uses, public fields, and thumbprints in a JWKS file.
JWKS Key Finder
Search a pasted JWKS for a matching kid and copy the exact public key.
PEM to JWK Converter
Convert a public SPKI or private PKCS8 RSA or EC key into JWK format.
Symmetric JWK Generator
Generate a 256-bit secret JWK for HS256 signing or A256GCM encryption.
Developer Tools: JWS & JWE
JWE Text Decryptor
Decrypt a direct A256GCM compact JWE with the passphrase used to make it.
JWE Text Encryptor
Protect text with direct A256GCM encryption and a passphrase-derived local key.
JWS Message Signer
Create a compact JWS for a text message with a shared secret kept in this tab.
JWS Signature Verifier
Check an HS256 compact JWS and reveal its text only after the signature matches.
Developer Tools: JWT Signing & Checks
JWT Claims Validator
Verify an HS256 token and require the issuer and audience your app expects.
JWT HS256 Signer
Turn JSON claims into a signed HS256 token with a secret that stays in this tab.
JWT Private Key Signer
Create an RS256 or ES256 token from claims and a local JWK or PKCS8 private key.
JWT Public Key Verifier
Verify an RS256 or ES256 token with a local public JWK or SPKI key.
JWT Signature Verifier
Check whether a JWT matches a shared secret, then read the verified claims.
Developer Tools: Numbers & Reports
JSON Average Calculator
Calculate the simple average of numbers collected from JSON records.
JSON Boolean Rule Checker
Evaluate a JSONata condition and return one clear true or false result.
JSON Data Summary Maker
Combine counts, totals, averages, and distinct values into one result object.
JSON Key Inventory
Use $keys to list top-level keys and the shared keys found in array records.
JSON Min and Max Finder
Return the minimum and maximum values from one numeric JSON field.
JSON Total Calculator
Sum numbers from a JSON array without moving the data into a spreadsheet.
JSON Value Type Inspector
Use $type to report the JSON type at several useful paths.
Developer Tools: Parse & Understand
JavaScript AST Explorer
Parse JavaScript into a clear table of syntax nodes and a downloadable AST.
JavaScript AST JSON Exporter
Parse JavaScript with locations and export its capped Acorn AST as JSON.
JavaScript Syntax Checker
Find the first JavaScript syntax error with its line, column, and nearby code.
JavaScript Syntax Error Explainer
Show the broken line, exact caret, parser message, and a short fix hint.