Developer Tools

Compare two .env files and report added/removed/changed keys while ignoring comments and blank lines.

Generate a .env template from a list of keys. Useful for projects and deployment checklists.

Convert Apache .htaccess directives into equivalent Nginx server block configuration. Handles RewriteRule, RewriteCond, Redirect, headers, expires, deny rules and directory index.

Generate test cases for API rate limiting and logic flaws.

Simulate API response delays for testing application behavior under latency.

Generate realistic fake data for testing, seeding databases and building interfaces before the backend exists.

Simulate request bursts to visualize token bucket algorithms.

Convert ASCII / Unicode decimal character codes back into text. Accepts space, comma or line separated numbers. Free, private, browser-based.

Complete ASCII code reference table.

Encode text to Base32 and decode Base32 back to text using the standard RFC 4648 alphabet. Useful for TOTP secrets and case-insensitive encoding. Free, private.

Encode text to Base58 and decode Base58 back to text using the Bitcoin alphabet (no 0, O, I, l). Useful for crypto, short IDs and human-friendly encoding. Private.

Encode text to Base64 and decode Base64 back to text, with full UTF-8 support and optional URL-safe output. Runs entirely in your browser.

Encode files to Base64 or a data URI in your browser, with the size and caching trade-offs stated up front.

Encode and decode Base64URL, the URL safe variant used by JWT, WebAuthn, OAuth PKCE and JOSE. Handles missing padding and shows the difference from standard Base64 byte by byte.

Generate secure Bcrypt hashes with custom cost factors.

Calculate cyclomatic and cognitive complexity, and interpret the numbers without misusing them.

Find the closest named CSS color for any HEX or RGB value, with the exact match indicator and the named color's HEX. Handy for design and CSS. Free, private, instant.

Compose a Conventional Commits message with the right type, scope, breaking change marker and footers, and validate an existing message against the specification.

Work out why a CORS request is blocked and which response header the server is missing.

Build and decode cron expressions with a plain-English explanation and the next run times. Covers standard five-field and extended formats.

Enter a five field cron expression and see the next ten times it will actually fire, computed minute by minute rather than guessed. Handles ranges, steps, lists and name aliases.

Explain cron expressions in plain English. Visual field breakdown, preset examples, and next 8 scheduled run times calculator.

Minify CSS by stripping comments and whitespace safely. Runs in your browser with no upload, and reports the byte saving before and after gzip.

Calculate CSS selector specificity and understand why a rule loses to another that looks less specific.

Convert a block of CSS declarations into the equivalent Tailwind utility classes, with arbitrary value syntax where no default scale value matches and a clear list of anything that has no utility.

Generate CSS code for triangles.

Convert CSV to JSON in your browser, with correct handling of quoted fields, embedded commas and the type-guessing traps.

Turn CSV rows into SQL INSERT statements with correct escaping, type handling and batching for large files.

Build cURL requests with headers, auth, and JSON body. Copy a clean command for terminal use.

Convert a cURL command into a JavaScript fetch() snippet (basic conversion).

Convert a cURL command into basic code snippets for Python requests, Node fetch, PHP cURL, and Go net/http.

Paste a package.json or requirements.txt to flag known-vulnerable versions, unpinned ranges, git URLs and abandoned packages against a built-in advisory list. Runs in your browser.

Compare two blocks of text and see added, removed and changed lines highlighted. Word-level and line-level diff, running entirely in your browser.

Generate common Docker tags and push commands from image name, version, and optional registry/namespace.

Convert a .env file into JSON, with correct handling of quoting, multi-line values, comments and exported variables.

Compare two .env files safely in your browser to find missing keys.

Generate an eslint.config.js flat config with Prettier for JavaScript or TypeScript, Node or browser, plus .prettierrc and a legacy .eslintrc.json.

Find the right Git command for your task.

Generate GitHub Actions CI workflows for Node.js, PHP, and Python projects. Copy YAML and save to .github/workflows/ci.yml.

Generate a .gitignore file for common stacks (Node, Python, PHP, Java, .NET) and OS files.

Format a GraphQL query, mutation or schema document with consistent indentation, or minify it for transport. Reports unbalanced braces with the line number where the nesting broke.

Visual tool to generate CSS Grid layouts.

Decode hexadecimal byte values back into readable UTF-8 text. Ignores 0x prefixes, spaces and commas automatically. Free, private, instant.

Generate 301/302 redirects for .htaccess.

Check markup against WCAG criteria that can be tested automatically, and know which ones cannot be.

Convert HTML entities back to characters.

Encode text as HTML entities so special characters display correctly instead of being interpreted as markup.

Minify HTML by removing comments and redundant whitespace, without breaking inline elements or pre blocks. Runs entirely in your browser.

Generate clean, ready-to-paste HTML table code from CSV or tab-separated data, with optional header row, table classes and live preview. Private & instant.

Convert raw HTML into valid JSX: renames class and for, camelCases attributes and event handlers, converts inline styles to objects, self closes void elements and escapes stray braces.

Convert HTML into clean Markdown in your browser. Handles tables, nested lists, links and code blocks, and strips presentational markup.

List and explanation of HTTP status codes.

Complete HTTP status code reference from 1xx to 5xx. Searchable with color-coded categories and detailed descriptions for each code.

Understand what specific status codes mean security-wise.

Convert an image to a Base64 data URI for inlining in HTML, CSS or JSON. Encoded in your browser with no upload.

Generate regex and rules for input fields.

Validate ISBN-10 and ISBN-13 book numbers by verifying the check digit, and convert between the two formats. Paste a list to validate many at once. Free, private.

Convert ISO 8601 duration strings such as P1DT2H30M into seconds, minutes and a plain English description, and build a duration string from any combination of units.

Convert a JavaScript object literal into valid JSON, handling unquoted keys, single quotes, trailing commas and comments.

Compare two JSON documents structurally rather than as text, so key order and formatting differences do not create false positives.

Flatten a nested JSON object into a single level of dot-notation keys (and unflatten it back). Perfect for configs, i18n files and CSV prep. Free, private, instant.

Format and beautify JSON in your browser. Pinpoints syntax errors by line and column, flags unsafe integers, and never uploads your data to a server.

Generate an RFC 7386 JSON Merge Patch between two documents, or apply a patch to a document. Shows exactly which keys are set, replaced and deleted by the null convention.

Strip insignificant whitespace from JSON to reduce payload size, with an honest account of how much it actually saves.

Generate a TypeScript interface from a JSON Schema (simplified conversion).

Sort JSON keys recursively to make files diff cleanly and compare reliably.

Generate a simple C# class skeleton from example JSON.

Generate Dart model classes from a JSON sample with null safe types, nested classes, typed lists and working fromJson and toJson methods for Flutter projects.

Generate a Go struct skeleton from example JSON.

Generate GraphQL SDL type definitions from a sample JSON response. Infers scalars, nullability, list types and nested object types, and names them from the keys they came from.

Generate a simple Java POJO class skeleton from example JSON.

Generate Kotlin data classes from a JSON sample with nullable types, nested classes, List element types and SerialName or SerializedName annotations for keys that are not idiomatic Kotlin.

Convert JSON objects into modern PHP array syntax [].

Generate Python dataclasses with full type hints from a JSON sample, including nested classes, Optional fields, list element types and a from_dict constructor.

Convert a JSON object into a URL query string with proper encoding, supporting arrays and nested values. The reverse of a query-string parser. Free, private, instant.

Generate Rust structs with serde derives from a JSON sample. Handles nested types, Option for nullable fields, Vec element types and serde rename attributes for non snake_case keys.

Turn a JSON array of records into a CREATE TABLE statement with inferred column types, nullability and lengths. Emits MySQL, PostgreSQL or SQLite dialects.

Generate a TypeScript interface/type from example JSON.

Convert JSON to XML in your browser, with the structural mismatches between the two formats made explicit.

Convert JSON to YAML format.

Validate JSON syntax with precise line and column errors, and check documents against a JSON Schema. Runs locally in your browser, nothing uploaded.

Generate a JSON Schema from example JSON. Supports objects, arrays, nested structures, and optional required fields.

Convert a JSON array to newline delimited JSON and back. Validates every line, reports the exact line number of a bad record, and keeps large exports out of any server.

Run a JSONPath expression against your own JSON and see every match with its full path. Supports dot and bracket notation, wildcards, array indexes, slices and recursive descent. Runs in your browser.

Create a signed HS256 JWT from a JSON payload and a secret, using the Web Crypto API in your browser. Nothing is sent anywhere.

Turn a plain list of lines into a JSON array, with control over trimming, blank lines, duplicates and type handling.

Paste logs to see what sensitive data (PII, Credits) gets masked.

Remove emails, IPs, API keys, JWTs, card numbers, phones and tokens from log text in your browser, with consistent placeholders so the log stays readable. Nothing is uploaded.

Build mailto: links with pre-filled to, cc, bcc, subject and body, properly URL-encoded, with ready-to-paste HTML.

Preview Markdown as rendered HTML in real time. Supports GitHub Flavored Markdown tables, task lists and fenced code. Runs entirely in your browser.

Turn CSV, TSV or pasted spreadsheet data into a clean, aligned Markdown table ready for GitHub, docs and READMEs. Choose column alignment. Private & instant.

Searchable list of MIME types and extensions.

Generate a Mongoose schema/model skeleton from example JSON.

Check whether a version satisfies an npm semver range, and see exactly which versions from a list a caret, tilde, comparator or hyphen range would install.

Convert numbers between binary, octal, decimal, hexadecimal and any base from 2 to 36, all at once. Great for programming and networking. Private & instant.

Visualize standard OAuth 2.0 flows.

Validate an OpenAPI or Swagger specification and catch the errors that pass validation but break generated clients.

Generate TypeScript types from OpenAPI components.schemas and list API endpoints (simplified).

Validate an npm package.json against the fields npm actually enforces: name rules, semver validity, dependency ranges, exports and files fields, licence identifiers and the mistakes that break publishing.

Paste a PHP array literal, a var_export dump or a config file return statement and get valid JSON back. Understands both array() and short syntax, nested arrays, constants and trailing commas.

Convert JSON to PHP serialized strings and vice versa for debugging.

A searchable reference of well-known TCP and UDP ports, what runs on them, and which ones should never face the internet.

Generate a Postman collection JSON from a list of endpoints. Useful for API testing and sharing.

Generate random strings with a chosen length and character set for tokens, test data, keys and identifiers.

Break a regular expression into its parts with a plain-language explanation of what each token matches.

Interactive regex tester with syntax highlighting, explanations, and match visualization.

Test regular expressions against sample text with live match highlighting, capture groups and flag control. Runs entirely in your browser.

Encode and decode text with the ROT13 and ROT47 ciphers. ROT13 is its own inverse, so the same tool encrypts and decrypts. Free, private, instant.

Estimate downtime and steps for rotating secrets.

Generate a checklist for specific languages (Java, JS, Python).

Generate secure coding checklists for JavaScript, Python, Java, and PHP.

Compute the next semantic version for major/minor/patch bumps and optionally add prerelease/build metadata.

Decode a Snowflake ID into its creation timestamp, worker, process and sequence numbers. Presets for Discord, Twitter/X, Instagram and Mastodon, plus a custom epoch mode.

Convert a list of values into a SQL IN () clause, with smart quoting for strings, no quotes for numbers, de-duplication and a ready-to-paste WHERE snippet. Private.

Escape or unescape strings for JSON, JavaScript, HTML entities and URL encoding. Handy for embedding text safely in code. 100% client-side and private.

Compare two strings with four established similarity metrics at once: Levenshtein edit distance, Jaro-Winkler, Sorensen-Dice bigrams and longest common subsequence. Useful for deduplication and fuzzy matching thresholds.

Convert SVG markup into an optimized URL-encoded data URI for use in CSS background-image, HTML img and JS, avoiding base64 bloat. Copy-ready output. Private.

Generate a basic tailwind.config.js with content globs and dark mode setting.

Convert text to its ASCII / Unicode decimal character codes, space or comma separated. Useful for debugging and encoding. Private and instant.

Convert text into hexadecimal byte values (UTF-8), with optional 0x prefix and separators. Great for debugging and encoding. Private and instant.

Convert a time between zones with correct daylight saving handling, and store timestamps so they stay correct.

Convert TOML into JSON in your browser with a complete parser covering tables, arrays of tables, inline tables, dotted keys, all four string forms and typed numbers and dates.

Break any text into its Unicode code points and see the hex value, UTF-8 bytes, HTML entity and escape forms for each. Flags invisible, bidirectional and homoglyph characters that break parsers and reviews.

Parse a URL into scheme, host, port, path, query parameters and fragment, with the parsing traps that cause security bugs.

Parse a URL or query string into a readable table of decoded key-value parameters, and rebuild it. Great for debugging links, UTM tags and APIs. Free, private, instant.

Measure text in characters, UTF-16 code units and UTF-8 bytes at once, and check whether it fits a VARCHAR, a DynamoDB key, an SMS segment or an HTTP header limit.

Generate UUIDs in bulk, and choose the version that suits how the values will be stored and sorted.

Generate cryptographically random UUIDs in your browser, with the differences between v1, v4 and v7 and when each is appropriate.

Validate one or many UUIDs and identify their version (v1–v5) and variant. Paste a list to check each line. Fast, free and 100% client-side.

Generate professional VAPT scope text for proposals.

Inspect webhook payloads and verify HMAC signatures, with the delivery guarantees you have to design around.

Format and indent XML with well-formedness checking, and understand where whitespace in XML is significant.

Convert XML to JSON in your browser, with attributes, mixed content and repeated elements handled explicitly.

Run an XPath expression against your own XML or HTML and see every matching node with its value and position. Uses the browser native XPath engine, so results match what a real parser returns.

Convert YAML to JSON and JSON to YAML in your browser. Handles anchors, multi-line strings and the classic YAML type-coercion traps.

Convert YAML to JSON in your browser, with the type-coercion traps that silently change values during conversion.

Generate a Zod schema and inferred TypeScript type from example JSON.