Catalog
All developer tools
Search 114 utilities — filter by suite, or jump straight in with a query.
All tools
114 tools
JSON Formatter
Beautify, minify, sort, and validate JSON entirely in the browser.
OpenJSON → TS
Infer TypeScript interfaces, type aliases, or Zod schemas from sample JSON.
OpenJWT Debugger
Decode JWT header, payload, and signature in-browser with expiry countdown.
OpencURL → Code
Paste a cURL command and get Go net/http, Python requests, fetch, and Axios.
OpenRegex Tester
Test JavaScript regular expressions with matches, groups, flags, and replace.
OpenUUID Generator
Bulk-generate UUID v4, UUID v7, NanoID, and high-entropy API keys locally.
OpenSQL Formatter
Pretty-print SQL for PostgreSQL, MySQL, SQLite, MariaDB, and T-SQL.
OpenBase64 Studio
Encode or decode Base64 online — text, images, PDFs, files — free, no upload.
OpenHash Generator
SHA-1, SHA-256, SHA-384, SHA-512, MD5, and HMAC from text or files in-browser.
OpenUnix Timestamp
Convert epoch seconds and milliseconds to ISO time, local time, and time zones.
OpenYAML / TOML
Convert YAML, JSON, and TOML in the browser.
OpenXML ↔ JSON
Convert XML to JSON and run XPath locally.
OpenCSV ↔ JSON
Parse CSV to JSON objects and emit INSERT statements.
OpenJSON Flatten
Flatten nested JSON, rebuild it, and query with JSONPath.
OpenJSON Schema
Validate JSON against a schema and infer a draft from a sample.
OpenJSON Diff
Diff two JSON documents and deep-merge objects locally.
OpenJSONL
Split, join, and sample newline-delimited JSON.
OpenHTML ↔ MD
Convert Markdown to HTML and HTML back to Markdown locally.
Open.env ↔ JSON
Turn dotenv files into JSON and back.
OpenTables
Convert HTML tables, CSV, and Markdown tables locally.
OpenULID / KSUID
Generate time-sortable IDs locally with Web Crypto.
OpenBase32 / 58 / 85
Encode and decode Base32, Base58, and Ascii85 in the browser.
OpenAES-GCM
Encrypt and decrypt with AES-GCM and PBKDF2 in Web Crypto.
OpenTOTP / HOTP
Generate TOTP codes and otpauth URIs locally.
OpenJWT Generator
Sign HS256 tokens locally from a JSON payload.
OpenPassphrase
Generate high-entropy word phrases with Web Crypto.
OpenCheck digits
Luhn, Verhoeff, ISBN, and GSTIN format checks.
OpenRedactor
Mask JWTs, PEMs, AWS keys, and password assignments.
OpenPKCE / OAuth
Build S256 PKCE and an authorize URL. No token endpoint is called.
OpenCRC32
CRC-32 of text or file bytes in the browser.
OpenURL tools
Parse URLs, edit UTM params, and slugify paths.
OpenHTTP status
Look up status codes and common headers without leaving the tab.
OpenCORS
See if a browser would allow a cross-origin request.
OpenCookie builder
Compose Set-Cookie and Cache-Control directives.
OpenWebhook HMAC
Sign and verify Stripe, GitHub, Slack, and Razorpay webhooks locally.
OpenMIME detect
Guess MIME type from magic bytes in the browser.
Openrobots.txt
Generate robots.txt, sitemap.xml, and security.txt stubs.
OpenUser-Agent
Parse browser, OS, and device from a User-Agent string.
OpenCase converter
camelCase, snake_case, kebab-case, slugs, and accent folding.
OpenText diff
Unified diffs and apply patch in the browser.
OpenLine toolkit
Sort, unique, shuffle, reverse, trim, and grep lines locally.
OpenWord counter
Count words, characters, lines, and estimate reading time.
OpenSemver
Parse, bump, compare, and test caret ranges.
Opengitignore
Combine Node, Python, Go, Rust, Next, and Android ignore templates.
OpenUnicode
Code points, UTF-8 bytes, NFC/NFD, and a punycode hostname peek.
OpenEmail syntax
Check email syntax. No SMTP, no mailbox probe.
OpenJSON → INSERT
Turn JSON arrays or CSV into INSERT or PostgreSQL COPY.
OpenConnection string
Parse Postgres, MySQL, Mongo, Redis, and AMQP URLs. Never connects.
OpenCron
Build and decode cron in plain English — with next runs and a month preview.
OpenTime zones
Live times across common IANA zones.
OpenFake data
Generate fictional people for fixtures. Obviously fake emails.
OpenLorem
Placeholder paragraphs as text, Markdown, or HTML.
OpenDummy REST
Users, products, orders, and posts as JSON fixtures.
OpenDummy webhooks
Sample GitHub, Stripe, Slack, Razorpay, Shopify, and Twilio payloads.
OpenTest cards
Stripe, Razorpay, Cashfree, PayU, Braintree, Adyen, and more — sandbox test cards, UPI IDs, OTP rules, and Luhn tools.
OpenDummy files
Build a file of N bytes in memory and download it.
OpenPlaceholder
PNG/JPEG/WebP placeholders at any size, in-browser.
OpenQR Code Generator
Free online QR code generator with logo, colors, and shapes. Make a QR code for a URL, Wi-Fi, vCard, UPI, location, PDF, or text — download as PNG, SVG, or PDF. No sign up, no watermark, never expires.
OpenColor / contrast
HEX, RGB, HSL, and WCAG contrast ratios in the browser.
OpenZIP
Build a zip or list files inside one. All in memory.
OpenINI / JSON5
Convert INI, .properties, JSON5, and JSONC in the browser.
OpenGraphQL
Pretty-print GraphQL and emit a fetch snippet.
OpenDynamoDB JSON
Convert AttributeValue maps to plain JSON and back.
OpenOpenAPI
Parse OpenAPI JSON or YAML and emit cURL / fetch for the first path.
OpenHex dump
Dump text or a local file as hex, and decode hex to UTF-8.
OpenRSA / ECDSA
Generate RSA-PSS 2048 or ECDSA P-256 keys and sign locally.
OpenPEM / JWK
Convert PEM and JWK, and emit ssh-rsa from an RSA JWK.
OpenPassword KDF
PBKDF2-SHA256, htpasswd {SHA}, and bcrypt in the browser.
OpenCode → cURL
Turn a fetch, Axios, or requests snippet into cURL.
OpenRaw HTTP
Parse a raw request or response and emit fetch.
OpenCSP
Build Content-Security-Policy and related isolation headers.
OpenHTTP composer
Build a raw HTTP request and fetch snippet. Nothing is sent.
OpenAuth headers
Build Authorization: Basic, Bearer, and a Digest example.
OpenRate limit
Parse Retry-After and X-RateLimit-* headers.
OpenDNS builder
Build A, AAAA, CNAME, MX, TXT, SRV, and CAA records. No live lookup.
OpenSPF / DMARC
Build SPF and DMARC TXT records and a DKIM placeholder. No DNS query.
OpenApp links
Build iOS AASA and Android Digital Asset Links files.
OpenCF _headers
Build Cloudflare Pages _headers and _redirects stubs.
OpenAWS SigV4
Build a SigV4 canonical request and optional HMAC signature. No AWS call.
OpenSimilarity
Levenshtein, Jaro, and Dice coefficients in the browser.
OpenPhone
Parse and format numbers with libphonenumber-js. No carrier lookup.
OpenIntl
Number, date, relative, list, and plural formatting via Intl.
OpenLine endings
Detect LF, CRLF, CR, convert them, and strip or add a UTF-8 BOM.
OpenANSI HTML
Turn ANSI color codes into HTML you can preview.
OpenSPDX
Browse common SPDX license identifiers and generate a LICENSE file stub.
OpenCommits
Build a Conventional Commits message with type, scope, and breaking.
Openi18n strings
Convert Android, iOS, gettext, ARB, and JSON string maps.
OpenExcel date
Convert Excel serial numbers to ISO-8601 and back.
OpenISO duration
Parse P1DT2H-style durations and test interval overlap.
OpenBusiness days
Add weekdays, count them, and compute an SLO error budget.
OpenOnCalendar
Translate a 5-field cron into a systemd OnCalendar= line.
OpenDummy logs
Generate JSON, logfmt, Apache, Nginx, or syslog lines.
OpenDummy CSV
Generate a CSV of fake people for importer tests.
OpenICS / vCard
Generate a one-event .ics and a simple vCard.
OpenDummy .env
Node, Next.js, and Docker Compose .env stubs.
OpenIndia fixtures
Format-check PAN, GSTIN, IFSC, and UPI. Sample values included.
OpenUnicode torture
Zalgo, RTL, ZWJ emoji, homoglyphs, BOM, and long lines for input tests.
Openproblem+json
Build an application/problem+json document.
OpenIdenticon
SHA-256 identicon PNG from a seed, drawn on canvas.
OpenResize
Resize a local image with canvas. PNG, JPEG, or WebP out.
OpenImage convert
Convert a local image between PNG, JPEG, and WebP on canvas.
OpenMarkdown preview
Preview Markdown as HTML and extract a table of contents.
OpenMeta tags
Generate title, Open Graph, Twitter card, and WebSite JSON-LD.
OpenCSS units
Convert px and rem, build clamp(), and a modular type scale.
OpenWeb manifest
Build a web app manifest.json with icons placeholders.
OpenCIDR
Network, mask, range, host count, and containment for IPv4 CIDR.
Opengzip
Compress and decompress gzip or deflate with CompressionStream.
OpenDeep links
Android intent URLs, iOS associated-domains stub, and custom schemes.
OpenMoney
Format amounts with Intl and a small ISO 4217 catalog.
OpenLog pretty
Pretty-print JSON lines and logfmt into JSON objects.
OpenApp icons
Design and export iOS, Android adaptive, and PWA icon packs in your browser.
OpenImage compressor
Free online image compressor that compresses a photo to an exact size in KB or MB — 20 KB, 50 KB, 100 KB, 200 KB, 500 KB, 1 MB — without losing quality. JPG, JPEG, PNG, and WebP. No upload, no sign up, no watermark.
OpenScreenshot Studio
Design store screenshots with device frames, templates, and text — all in your browser.
OpenP2P file transfer
Free P2P file sharing online with a 6-digit code or QR. WebRTC sends files straight phone ↔ laptop — nothing uploaded to a server, no size limit from us, bi-directional while you stay connected.
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