Developer tools we built because we needed them
Every one is backed by a real API rather than a snippet of browser JavaScript - which is the point. They are free, there is no sign-up, and they double as a working sample of how we build.
Inspect
5Endpoint Inspector
HTTP status, response time, redirect chain, TLS certificate and a security-header grade for any URL. SSRF-safe.
Open the toolWebhook / Request Inspector
Get a unique URL and watch incoming HTTP requests land in real time over a WebSocket - method, headers, query and body.
Open the toolHTTP Request Builder
A mini Postman: build any request, send it server-side, and inspect the full response - status, headers, timing and body. SSRF-safe.
Open the toolDNS & WHOIS Lookup
Resolve a domain’s DNS records (A, AAAA, CNAME, MX, NS, TXT) and registration details - registrar, created, expiry - via RDAP.
Open the toolLive Status Monitor
A real uptime monitor - endpoints checked every 60s with uptime percentage and response-time history. Add any URL to watch it live for 24 hours.
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Build
4Instant Mock API
Design a resource and get a live REST endpoint serving realistic, deterministic fake data - pagination, filtering, sorting, search and simulated writes. Prototype a front end before the backend exists.
Open the toolQR Code Generator
Turn any URL or text into a crisp QR code, generated server-side. Download as SVG or PNG.
Open the toolLorem Ipsum Generator
Placeholder text by paragraphs, sentences, words, characters or list items - as plain text or ready-to-paste HTML.
Open the toolURL Shortener
Shorten a link and track clicks - total, a 7-day trend and top referrers, computed in SQL. Links show a safe destination preview before redirecting.
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Convert
2Unix Timestamp Converter
Convert a Unix timestamp in seconds or milliseconds to a readable date and back - ISO, UTC, local and relative time, plus a live current epoch.
Open the toolCron Expression Explainer
Paste a cron expression to get a plain-English description and the next five run times in any timezone.
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Secure
4JWT Decoder & Verifier
Decode a JSON Web Token to inspect header and payload, check expiry, and verify the signature (HS* with a secret, RS*/ES* with a public key). Decoding stays in your browser.
Open the toolPassword Breach Checker
Check if a password appears in a known data breach - privately. Hashed in your browser, only a five-character prefix is sent (k-anonymity).
Open the toolOne-Time Secret
Share a password or note via a link that self-destructs after one view. Encrypted in your browser - the key never reaches the server.
Open the toolEmail Validator
Check an email address: valid syntax, a live MX-record lookup to see if the domain accepts mail, and disposable or role-based flags.
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We build tools like these for clients too
The same engineering that makes a free utility fast and reliable is what makes an internal platform worth using. Tell us what your team keeps doing by hand.