Developer
Developer
Regex, cron, diff, git helpers, HTTP, URL, mock APIs and dev workflow tools.
56 tools
cURL → Code / HTTP Request Importer
Paste a curl command, inspect the request shape, and export fetch, axios, or Python requests code.
OpenDocker Run to Compose Converter
Free docker run to docker-compose converter. Turn a long docker run command line into a clean Compose v3 service definition: image, container name, ports (-p), volumes (-v), environment (-e), --restart, --network, working dir (-w), entrypoint and trailing command. Live YAML preview, one-click copy, 100% in-browser.
OpenHTTP Request Builder
Free HTTP request builder: pick a GET/POST/PUT/PATCH/DELETE/HEAD/OPTIONS method, query params merged into the URL, headers and a raw or JSON body, then copy the live cURL, fetch and raw HTTP/1.1 output in one click. Nothing is ever sent — code generation only, 100% in-browser.
OpenJSONPath Tester
Free in-browser JSONPath tester. Paste a JSON document, type a JSONPath expression, and instantly see all matching values as a pretty-printed array. Supports the root $, child .key and ['key'] access, array [index], [*] wildcards, .. recursive descent and [start:end] slices, with one-click copy and live error banners.
OpenRegex Find & Replace
A client-side regex find-and-replace tool: enter a pattern, toggle flags, write a replacement with $1 / $<name> capture references, and watch the transformed text update live.
OpenBasic Auth Header Generator
Free in-browser tool to generate and decode an HTTP Basic Auth header from a username and password. UTF-8-safe Base64, Authorization header, curl examples, and a decode panel.
OpenConventional Commit Validator
A free, in-browser tool that validates commit messages against Conventional Commits 1.0.0, parsing the type, scope and body while listing errors and warnings.
OpenGit Cheat Sheet
A searchable quick reference of 50+ essential Git commands grouped into setup, staging, commit, branch, merge/rebase, remote, undo, stash, inspect, and tags.
OpenMeta Tag Generator
Generate, preview, and import every meta tag your page needs — SEO, Open Graph, Twitter and more.
OpenOpen Graph & Meta Tag Previewer
Preview how your title, description, URL, and image will look in Discord, X, and search results before publishing.
OpenOpenAPI / Swagger Validator
Structural validator for OpenAPI 3.x and Swagger 2.0 specs in JSON or YAML. Detects the version, requires info.title and info.version, checks every path item for valid HTTP methods and operation responses, and counts paths and operations.
OpenRedirect Rule Generator
A client-side tool that builds copy-paste redirect configuration for four popular servers from a list of from→to path pairs, using the status code you pick (301 or 302).
OpenRegex Cheat Sheet
Look up regex syntax fast: character classes, anchors, quantifiers, groups, lookaround, flags, and ready-made patterns for email, URL, IPv4, dates and more.
OpenSEO Audit Checklist
Free interactive on-page SEO audit checklist with 40+ actionable checks across seven categories. Tick items off, track a weighted completion score and per-category progress, then copy a markdown audit report. Your progress is saved locally in your browser.
OpenUser Agent Parser
Free User-Agent parser that breaks any User-Agent header into browser (Chrome, Firefox, Safari, Edge, Opera), layout engine (Blink, Gecko, WebKit, Trident), operating system (Windows, macOS, Linux, Android, iOS) and device type (desktop, mobile, tablet, bot). Prefilled with your own browser's string, with live parsing and one-click copy — 100% in-browser.
OpenAI Cost Estimator
Estimate and compare LLM API costs across OpenAI, Anthropic, Google, Mistral, Groq, DeepSeek, and more.
OpenAPI Mock Builder
Turn a sample response into reusable mock payloads, curl snippets, fetch calls, TypeScript types, and OpenAPI response blocks.
OpenGit Branch Name Generator
Free git branch name generator. Pick a type (feature, bugfix, hotfix, release, chore, docs), add an optional ticket id and a description, choose your separator and kebab- or snake-case, and get a clean, slugified branch name instantly. Unicode is transliterated, unsafe characters are stripped, everything runs in your browser.
OpenCode Minifier
Minify HTML, CSS, and JavaScript code by stripping whitespace, comments, and redundant characters.
OpenEmail Normalizer & Validator
Free email normalization and validation tool. Paste one address per line; each address is reduced to its canonical mailbox (Gmail/Googlemail dots and +tags removed, googlemail.com folded into gmail.com), validated, and duplicates are flagged. Live preview, one-click copy, 100% in-browser.
OpenKeyword Density Checker
An in-browser tool that analyzes the keyword density of a text, listing the most frequent phrases alongside word, character and sentence counts and reading time.
OpenMeta Robots Tag Generator
Generate a robots meta tag and X-Robots-Tag HTTP header with toggles for noindex, nofollow, noarchive, nosnippet, noimageindex, notranslate, max-snippet, max-image-preview, max-video-preview and unavailable_after.
OpenSystem Prompt Builder & Library
Build, lint, and compare system prompts for AI assistants — with a curated library of 30+ production-quality templates.
OpenUUID Validator & Inspector
Validate a UUID's 8-4-4-4-12 format and detect its RFC 9562 version and variant entirely in your browser.
OpenCode Line Counter
Free code line counter that classifies every line of pasted source as code, comment or blank. Choose a language so single-line markers (//, #, --) and block comments (/* */, <!-- -->) are detected correctly, then read the live totals, percentages and a proportion bar. Runs entirely in your browser.
OpenDiff Viewer
Compare two text blocks with a clear unified diff output and line counters.
OpenEnv File Manager
Parse .env files, surface duplicate keys and empty secrets, and generate a cleaner .env plus .env.example output.
OpenMAC Address Tools
A fully client-side tool that reformats a MAC address into four notations (colon, hyphen, Cisco dot and bare), resolves its vendor offline, and decodes the multicast and locally-administered bits. It also generates random MAC addresses.
OpenMCP Config Generator
Build, validate, and merge Model Context Protocol configs for Claude Desktop, Claude Code, Cursor, Cline, Continue, and Zed.
OpenRegex Tester + Cheatsheet
Test JS regex, inspect named groups, preview replacements, and avoid catastrophic backtracking.
OpenSERP Preview
Tune title, URL, and description and see exactly how Google, Bing and DuckDuckGo will render the snippet.
OpenCORS Tester & Generator
Build, simulate, analyze, and live-test CORS configurations across every server stack.
OpenCron Expression Builder
Build standard, AWS, and Quartz cron expressions with field inputs and upcoming run previews.
Open.gitignore Generator
Pick languages, frameworks, editors, OS, and tools — get a clean, deduped, opinionated .gitignore (or .dockerignore) in seconds.
OpenHTTP Header Analyzer
Read raw response headers, highlight missing security protections, and summarize cache and CORS behavior.
OpenREADME Generator
Build a polished README.md from toggleable sections — title, badges, features, installation, usage, API, tech stack, roadmap, license — with live Markdown preview.
OpenRegex Explainer
Break any regex pattern into plain-English token cards, see a railroad diagram, lint risky patterns, and translate across regex flavors.
OpenUTM Link Builder
Build, validate, and audit Google Analytics campaign URLs with naming convention enforcement and reverse parsing.
OpenWebhook Tester & Inspector
Build, send, and inspect HTTP requests in the browser. Headers, params, body, auth helpers, response inspector with cookies / headers / raw tabs, HMAC signature panel.
OpenHTTP Status Code Reference
Searchable dictionary of every standard HTTP status code with category color coding, common scenarios, what-to-do guidance, and copy-ready snippets for Express / Next.js / Go / Flask / Axum / curl.
OpenIPv4 Subnet Calculator
Full IPv4 subnet calculator — CIDR info, subnet splitter, VLSM allocator, range → CIDR converter, and a complete /1 → /32 reference table.
OpenBase64 / URL / HTML Encoder-Decoder
Encode or decode Base64, URL, and HTML entities in a single utility panel.
OpenConventional Commit Generator
Craft Conventional Commits 1.0.0 messages with live preview, breaking-change handling, footers, and copy-as-git-command.
OpenCookie Parser & Set-Cookie Builder
Parse Cookie or Set-Cookie lines, inspect attributes, and build a clean Set-Cookie header visually.
OpenPrompt Trimmer
Trim long prompts down to a token budget — boundary-aware, with strategies for chat history, document QA and code review.
OpenSitemap XML Generator
Generate, validate, and split sitemap.xml files with handling for 50k URL limits and image/video extensions.
OpenURL Parser
Bidirectional URL parser, builder, and diff tool — protocol, query params, path segments, Punycode, plus mailto / data / magnet decoders.
OpenFolder Tree Generator
Build beautiful ASCII folder trees for READMEs — point-and-click, paste indented text, or drop a folder.
OpenLicense Picker
Pick an open-source license through a guided quiz, browse 30 popular options, or compare them side-by-side.
OpenPhone Number Formatter
Format, validate, and extract phone numbers with Google's libphonenumber — entirely in your browser.
OpenTwitter / X Card Generator
Build a pixel-perfect Twitter / X card preview, validate against best practices, and copy a head-ready snippet or Next.js Metadata literal.
Openchmod Calculator
Convert POSIX file permissions between octal, symbolic, and a checkbox grid — with chmod commands and security warnings.
OpenHeading Structure Checker
Audit H1–H6 hierarchy, catch SEO and accessibility issues, and export a clean document outline.
OpenHreflang Tag Generator
Generate, validate, and audit hreflang tags in HTML, HTTP header, XML sitemap, Next.js Metadata, and JSON.
Openrobots.txt Builder
Visually build, parse, and test robots.txt files with rule matching that follows Google's spec.
OpenMIME Type Lookup
Search 250+ MIME types, swap extensions and content types, and see what the browser thinks your file really is.
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