63 tools
Browser-based developer tools — no upload
The Developer Toolbox is a set of everyday utilities that run entirely client-side — paste, transform, and copy without anything leaving your browser.
There is no upload endpoint — your files are processed in this browser tab. Open your network tab and check. See how it stays private.
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All 63 tools in Developer Toolbox
- Format & minifyPrettify or minify HTML, CSS, JavaScript, TypeScript, and JSON entirely in your browser.
- Text diffCompare two blocks side-by-side with highlighted line differences.
- Regex playgroundTest regular expressions against sample text with match highlighting.
- JSON toolkitFormat, validate, minify, and explore JSON in a collapsible tree — all in your browser.
- YAML formatterFormat and validate YAML locally with helpful parse errors.
- XML formatterPretty-print or minify XML in your browser with no upload.
- SQL formatterBeautify SQL for many dialects locally with sql-formatter.
- JSON / YAML / TOMLConvert between JSON, YAML, and TOML data formats on your device.
- cURL to codeTurn a cURL command into fetch, axios, Python requests, or Go — locally.
- TimestampConvert Unix timestamps to dates across timezones in your browser.
- Case converterConvert text between camelCase, snake_case, kebab-case, and more.
- Number baseConvert between binary, octal, decimal, and hexadecimal.
- Color converterConvert colors between HEX, RGB, and HSL with a live preview.
- JSON to typesInfer TypeScript interfaces, Go structs, or Zod schemas from JSON samples.
- Password generatorGenerate strong random passwords or passphrases with Web Crypto.
- ULID / NanoIDBatch-generate ULIDs and NanoIDs locally with Web Crypto.
- Lorem IpsumGenerate placeholder paragraphs, sentences, or words.
- .gitignoreBuild a .gitignore from common language and framework templates.
- LICENSEFill in a popular open-source license with your name and year.
- DockerfileGenerate a starter Dockerfile for common runtimes.
- README badgeBuild README badge Markdown for shields.io locally.
- Meta / OG tagsGenerate SEO, OpenGraph, and Twitter meta tags for a page.
- robots.txtBuild a robots.txt with allow/disallow rules and sitemap.
- QR codeGenerate a QR code (URL, WiFi, vCard, text) as PNG or SVG locally.
- HTTP status codesSearch HTTP status codes with meanings and categories.
- HTTP headersLook up common HTTP request and response headers.
- MIME typesFind MIME content types by file extension.
- Common portsSearch common TCP/UDP ports and their services.
- ASCII tableBrowse ASCII codes in decimal, hex, octal, and binary.
- Regex cheatsheetQuick reference for regular expression tokens and patterns.
- SemVer rulesReference for semantic version ranges and operators.
- Date tokensReference for strftime and date-fns format tokens.
- Base64Encode or decode Base64 text and files locally.
- URL encodeEncode or decode URI components without sending data anywhere.
- HTML entitiesEscape or unescape HTML entities for safe markup.
- Hex / ASCII / binaryConvert text between hex, ASCII, and binary representations.
- Unicode inspectorInspect code points, escapes, and encodings of any string.
- String escapeEscape strings for JSON, SQL, shell, and regex contexts.
- Base32 / Base64URLEncode or decode Base32 and Base64URL locally.
- Gzip / BrotliCompress text with gzip or brotli and compare byte sizes locally.
- URL parserBreak a URL into protocol, host, path, and editable query parameters.
- CIDR calculatorCompute network address, broadcast, and host range for IPv4 CIDR blocks.
- User-Agent parserBreak down browser, OS, and device hints from a raw UA string.
- IPv4 / IPv6Convert IPv4 to integer and binary, and expand or compress IPv6.
- MAC / OUINormalize a MAC address and read its OUI and local/multicast bits.
- Query stringParse and build URL query strings with a key/value editor.
- Security headersBuild CSP, HSTS, CORS, and Permissions-Policy headers plus SRI hashes.
- HTTP clientSend HTTP requests directly from your browser (subject to CORS).
- WebSocket testerConnect to a WebSocket endpoint and send/receive messages.
- Cron explainerType a cron expression and get a plain-English summary of when it runs.
- Chmod calculatorToggle Unix permission bits and see the numeric mode (e.g. 755, 644).
- Compose validatorParse and validate docker-compose.yml syntax locally.
- UUID generatorGenerate batches of RFC 4122 version 4 UUIDs instantly.
- HAR viewer + scrubInspect a .har capture and strip auth tokens and cookies before sharing.
- SQLite browserOpen a .sqlite file and run read-only queries with sql.js in your browser.
- Source map resolverResolve a generated line/column to the original source via a source map.
- Protobuf decoderDecode raw protobuf bytes into field numbers, wire types, and values.
- PCAP viewerParse a .pcap capture and list packets with timestamps and lengths.
- .env manager & diffParse, edit, and diff two .env files locally to spot missing keys.
- Secret scannerScan pasted code or config for API keys, tokens, and private keys.
- K8s secret decodeDecode base64 values in a Kubernetes Secret manifest locally.
- Config converterConvert config between .env, JSON, YAML, and TOML on your device.
- htpasswd generatorGenerate bcrypt .htpasswd entries locally for basic auth.