Changelog
Ce qu’on a
livré.
Chaque fonctionnalité, fix et amélioration de FerrLens. Vue inter-produits sur ferrlabs.com/changelog.
RSSCT log search
Find every TLS certificate ever issued for a domain by querying the public Certificate Transparency logs (crt.sh) — great for subdomain discovery and rogue-cert detection.
CORS tester
Send a preflight + actual request from a configurable Origin and see exactly which CORS headers the server returns — with pass/fail diagnostics.
Mixed content scanner
Scan an HTTPS page for HTTP-only src / href / action / poster / data-src resources that modern browsers block.
OG card preview
See how a URL renders as a Twitter card, LinkedIn share and Slack unfurl — side by side, with warnings for missing or oversized fields.
Meta tag inspector
Fetch any URL and see every meta + link tag grouped by namespace — standard, OpenGraph, Twitter, Facebook, http-equiv, link.
ASCII / Unicode inspector
Codepoint-by-codepoint breakdown of any string — UTF-8 bytes, UTF-16 units, HTML entities, CSS escape and Unicode block.
Punycode converter
Internationalised domain names (IDN) to ASCII Punycode and back, using the browser's native URL parser.
IP / CIDR calculator
IPv4 and IPv6 CIDR math — network, broadcast, usable host range, netmask, total hosts, and address classification.
User-Agent parser
Break down any User-Agent string into browser, engine, OS, device and bot heuristics — no remote call.
HTTP status lookup
Searchable dictionary of HTTP status codes — number, reason phrase, category and what each one actually means in practice.
Sitemap validator
Fetch a sitemap.xml or a sitemap index, validate the XML, list child sitemaps or sample the URLs with lastmod / changefreq / priority.
Robots.txt analyzer
Fetch and parse a domain's robots.txt, simulate a crawl decision for any User-Agent + path, list every declared sitemap.
Security headers grader
Score any URL on CSP, HSTS, X-Frame, X-Content-Type, Referrer-Policy, Permissions-Policy, COOP and CORP. A+ to F grade out of 90 points.
HTTP header inspector
Fetch any URL, see every response header, the full redirect chain, and the time it took. Like curl -ILv but rendered nicely.
Reverse DNS
IP address (v4 or v6) → PTR hostname lookup. Useful for tracing the rDNS of a mail server or checking that your IP resolves to the hostname you think it does.
DNS lookup
A · AAAA · MX · TXT · NS · SOA · SRV in one shot, queried in parallel against Cloudflare's public resolvers.
FerrLens · Diff tool is live
Paste two blobs, get a side-by-side or unified diff with inline character highlights. Whitespace and case toggles. Fully client-side — the URL fragment encodes both inputs so you can share without uploading anything.
FerrLens · Dates now render in your local timezone
Snapshot timestamps and scan-fetched-at on shared SEO pages used to render in the server's timezone. They now show in yours. Plus a reusable SSE hook so future streaming tools share the same pattern as the SEO checker.
Spam score — SpamAssassin-style heuristics
Drop a subject + body, get a 0-10 spam score with the exact rules that flagged each line. Runs entirely in your browser — your draft never leaves the page.
Email verifier (v0)
Syntax + MX record check + disposable-provider list + role-based local-part detection. Real SMTP probe comes later.
DNSBL blacklist checker
Query an IP or domain against 30 major DNSBLs (Spamhaus, SpamCop, Barracuda, SORBS, UCEProtect, Mailspike, …) in parallel. Verdict in under a second.
SPF / DKIM / DMARC inspector
Pull, parse and score a domain's email-authentication TXT records — SPF mechanisms, DMARC policy + reports, ~30 common DKIM selectors checked in parallel.
FerrLens disponible en français
38 nouvelles routes /fr/ — home, pricing, account, les 8 pages légales, le changelog et les 21 outils — avec un sélecteur EN/FR en haut de chaque page.
Compressed, opaque share links
Share links from any tool now embed state as a single lz-string-compressed JSON blob instead of plain key=value pairs — 30-70% shorter, no longer human-readable.
FerrLens · SEO checker is now live-streaming, and ~3× faster
The SEO checker no longer waits 20 s before showing anything. Core Web Vitals appear in ~3 s, then full Lighthouse scores fill in. Chromium is now pooled, K8s right-sized, perf flags fixed.
Text stats
Characters, words, lines, sentences, paragraphs, reading time and approximate LLM token count for any block of text.
Credit card / IBAN validator
Validate credit card numbers with the Luhn algorithm and issuer detection, or IBANs with a mod-97 check and per-country length validation.
File hash
Drop a file, get its MD5, SHA-1, SHA-256 and SHA-512 — computed locally, the file never leaves your browser.
JWT signature verify
Verify a JWT against a public key (PEM or JWK) — HS, RS, PS and ES families, all algorithms — through the native Web Crypto API.
Number base converter
Convert between binary, octal, decimal and hex with BigInt arithmetic — no precision loss even on 128-bit numbers.
Slugify
Turn any string — accented, punctuated, multi-word — into a clean URL slug. Configurable separator, max length, and case.
Case converter
Convert between 11 case styles — camelCase, PascalCase, snake_case, SCREAMING_SNAKE, kebab-case, COBOL-CASE, dot.case, Title Case, Sentence case, lower, UPPER.
FerrLens · User menu with tier badge in the navbar
Signed-in users now see an avatar + tier pill in the FerrLens navbar instead of a plain Account link. The dropdown surfaces email, plan, Upgrade CTA and Sign out.
Password generator
Generate strong passwords with configurable charsets, a "no look-alikes" mode, an entropy bar and a crack-time estimate — backed by crypto.getRandomValues.
Color converter
HEX ↔ RGB ↔ HSL ↔ OKLCH with a live colour preview, alpha-aware.
Timestamp converter
Convert between Unix seconds, Unix milliseconds and ISO 8601, with a live view in any IANA timezone plus a relative reading ("3 days ago").
HMAC generator
Generate HMAC-SHA1/256/384/512 of a message with a key in UTF-8, hex or Base64 — through the native Web Crypto API, in your browser.
URL / Base64 / Base64-URL / hex encoder
Encode and decode between text and URL-percent / Base64 / Base64-URL (RFC 4648 §5) / hex, with a single shared input that toggles direction in one click.
Hash generator
MD5, SHA-1, SHA-256, SHA-384 and SHA-512 of any input. SHA-* through the native Web Crypto API, MD5 through a small pure-JS implementation. Your input never leaves the browser.
FerrLens · Sign in with your FerrLabs account
ferrlens.com now uses the central FerrLabs identity, so the same account works across every product site. Cross-domain auth handled server-side by the Astro SSR layer — no token in JavaScript.
FerrLens · SEO checker runs Lighthouse locally
ferrlens.com now runs a real Lighthouse against a real Chromium in-cluster, instead of waiting for Google PageSpeed Insights. Faster, no quota, more signals.