# Browser-based developer tools — no upload

> 60+ developer utilities that run locally: format and convert JSON/YAML, decode JWTs, test regex, generate UUIDs, encode data and more. 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.

## Tools in this workspace

- [Format & minify](https://www.safepaper.app/dev/code-formatter): Prettify or minify HTML, CSS, JavaScript, TypeScript, and JSON entirely in your browser.
- [Text diff](https://www.safepaper.app/dev/text-diff): Compare two blocks side-by-side with highlighted line differences.
- [Regex playground](https://www.safepaper.app/dev/regex-playground): Test regular expressions against sample text with match highlighting.
- [JSON toolkit](https://www.safepaper.app/dev/json-toolkit): Format, validate, minify, and explore JSON in a collapsible tree — all in your browser.
- [YAML formatter](https://www.safepaper.app/dev/yaml-formatter): Format and validate YAML locally with helpful parse errors.
- [XML formatter](https://www.safepaper.app/dev/xml-formatter): Pretty-print or minify XML in your browser with no upload.
- [SQL formatter](https://www.safepaper.app/dev/sql-formatter): Beautify SQL for many dialects locally with sql-formatter.
- [JSON / YAML / TOML](https://www.safepaper.app/dev/data-convert): Convert between JSON, YAML, and TOML data formats on your device.
- [cURL to code](https://www.safepaper.app/dev/curl-to-code): Turn a cURL command into fetch, axios, Python requests, or Go — locally.
- [Timestamp](https://www.safepaper.app/dev/unix-timestamp-converter): Convert Unix timestamps to dates across timezones in your browser.
- [Case converter](https://www.safepaper.app/dev/case-convert): Convert text between camelCase, snake_case, kebab-case, and more.
- [Number base](https://www.safepaper.app/dev/number-base): Convert between binary, octal, decimal, and hexadecimal.
- [Color converter](https://www.safepaper.app/dev/color-convert): Convert colors between HEX, RGB, and HSL with a live preview.
- [JSON to types](https://www.safepaper.app/dev/json-to-types): Infer TypeScript interfaces, Go structs, or Zod schemas from JSON samples.
- [Password generator](https://www.safepaper.app/dev/password-gen): Generate strong random passwords or passphrases with Web Crypto.
- [ULID / NanoID](https://www.safepaper.app/dev/id-gen): Batch-generate ULIDs and NanoIDs locally with Web Crypto.
- [Lorem Ipsum](https://www.safepaper.app/dev/lorem-ipsum): Generate placeholder paragraphs, sentences, or words.
- [.gitignore](https://www.safepaper.app/dev/gitignore): Build a .gitignore from common language and framework templates.
- [LICENSE](https://www.safepaper.app/dev/license-gen): Fill in a popular open-source license with your name and year.
- [Dockerfile](https://www.safepaper.app/dev/dockerfile-gen): Generate a starter Dockerfile for common runtimes.
- [README badge](https://www.safepaper.app/dev/badge-gen): Build README badge Markdown for shields.io locally.
- [Meta / OG tags](https://www.safepaper.app/dev/meta-tags): Generate SEO, OpenGraph, and Twitter meta tags for a page.
- [robots.txt](https://www.safepaper.app/dev/robots-txt): Build a robots.txt with allow/disallow rules and sitemap.
- [QR code](https://www.safepaper.app/dev/qr-code): Generate a QR code (URL, WiFi, vCard, text) as PNG or SVG locally.
- [HTTP status codes](https://www.safepaper.app/dev/http-status-codes): Search HTTP status codes with meanings and categories.
- [HTTP headers](https://www.safepaper.app/dev/http-headers): Look up common HTTP request and response headers.
- [MIME types](https://www.safepaper.app/dev/mime-types): Find MIME content types by file extension.
- [Common ports](https://www.safepaper.app/dev/common-ports): Search common TCP/UDP ports and their services.
- [ASCII table](https://www.safepaper.app/dev/ascii-table): Browse ASCII codes in decimal, hex, octal, and binary.
- [Regex cheatsheet](https://www.safepaper.app/dev/regex-cheatsheet): Quick reference for regular expression tokens and patterns.
- [SemVer rules](https://www.safepaper.app/dev/semver-rules): Reference for semantic version ranges and operators.
- [Date tokens](https://www.safepaper.app/dev/date-format-tokens): Reference for strftime and date-fns format tokens.
- [Base64](https://www.safepaper.app/dev/base64): Encode or decode Base64 text and files locally.
- [URL encode](https://www.safepaper.app/dev/url-encoder): Encode or decode URI components without sending data anywhere.
- [HTML entities](https://www.safepaper.app/dev/html-entities): Escape or unescape HTML entities for safe markup.
- [Hex / ASCII / binary](https://www.safepaper.app/dev/hex-ascii): Convert text between hex, ASCII, and binary representations.
- [Unicode inspector](https://www.safepaper.app/dev/unicode-inspector): Inspect code points, escapes, and encodings of any string.
- [String escape](https://www.safepaper.app/dev/string-escape): Escape strings for JSON, SQL, shell, and regex contexts.
- [Base32 / Base64URL](https://www.safepaper.app/dev/base32): Encode or decode Base32 and Base64URL locally.
- [Gzip / Brotli](https://www.safepaper.app/dev/gzip): Compress text with gzip or brotli and compare byte sizes locally.
- [URL parser](https://www.safepaper.app/dev/url-parser): Break a URL into protocol, host, path, and editable query parameters.
- [CIDR calculator](https://www.safepaper.app/dev/cidr): Compute network address, broadcast, and host range for IPv4 CIDR blocks.
- [User-Agent parser](https://www.safepaper.app/dev/user-agent): Break down browser, OS, and device hints from a raw UA string.
- [IPv4 / IPv6](https://www.safepaper.app/dev/ip-convert): Convert IPv4 to integer and binary, and expand or compress IPv6.
- [MAC / OUI](https://www.safepaper.app/dev/mac-lookup): Normalize a MAC address and read its OUI and local/multicast bits.
- [Query string](https://www.safepaper.app/dev/query-string): Parse and build URL query strings with a key/value editor.
- [Security headers](https://www.safepaper.app/dev/security-headers): Build CSP, HSTS, CORS, and Permissions-Policy headers plus SRI hashes.
- [HTTP client](https://www.safepaper.app/dev/http-client): Send HTTP requests directly from your browser (subject to CORS).
- [WebSocket tester](https://www.safepaper.app/dev/websocket-tester): Connect to a WebSocket endpoint and send/receive messages.
- [Cron explainer](https://www.safepaper.app/dev/cron): Type a cron expression and get a plain-English summary of when it runs.
- [Chmod calculator](https://www.safepaper.app/dev/chmod): Toggle Unix permission bits and see the numeric mode (e.g. 755, 644).
- [Compose validator](https://www.safepaper.app/dev/docker-compose): Parse and validate docker-compose.yml syntax locally.
- [UUID generator](https://www.safepaper.app/dev/uuid): Generate batches of RFC 4122 version 4 UUIDs instantly.
- [HAR viewer + scrub](https://www.safepaper.app/dev/har-viewer): Inspect a .har capture and strip auth tokens and cookies before sharing.
- [SQLite browser](https://www.safepaper.app/dev/sqlite-browser): Open a .sqlite file and run read-only queries with sql.js in your browser.
- [Source map resolver](https://www.safepaper.app/dev/sourcemap-resolver): Resolve a generated line/column to the original source via a source map.
- [Protobuf decoder](https://www.safepaper.app/dev/protobuf-decoder): Decode raw protobuf bytes into field numbers, wire types, and values.
- [PCAP viewer](https://www.safepaper.app/dev/pcap-viewer): Parse a .pcap capture and list packets with timestamps and lengths.
- [.env manager & diff](https://www.safepaper.app/dev/env-manager): Parse, edit, and diff two .env files locally to spot missing keys.
- [Secret scanner](https://www.safepaper.app/dev/secret-scanner): Scan pasted code or config for API keys, tokens, and private keys.
- [K8s secret decode](https://www.safepaper.app/dev/k8s-secret): Decode base64 values in a Kubernetes Secret manifest locally.
- [Config converter](https://www.safepaper.app/dev/config-convert): Convert config between .env, JSON, YAML, and TOML on your device.
- [htpasswd generator](https://www.safepaper.app/dev/htpasswd): Generate bcrypt .htpasswd entries locally for basic auth.

Each tool also has a Markdown mirror at its URL plus `.md` (for example https://www.safepaper.app/dev/code-formatter.md).

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Canonical HTML: https://www.safepaper.app/dev
Markdown: https://www.safepaper.app/dev.md

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