43 Free Tools for Webmasters: The Complete Catalogue

You do not need a paid subscription to check a website. Most tasks — from “why do my emails land in spam” to “why is this page missing from Google” — are solved by free tools in a couple of minutes. The real problem is different: there are hundreds of such services, half of them are buried in ads, and some demand registration for a single lookup.

We have gathered 43 tools in one place and keep them free of ads, registration and usage limits. Below is the full list by category, with a note on when each one is useful.

What to know before you start

Some of the tools run entirely in your browser — the data never leaves your computer. This applies to everything involving files and personal information: the image converter, QR code reader, tax ID and IBAN validators, JSON formatter and text comparison. It is easy to verify: open the Network tab in developer tools and you will see no requests at all while you work.

The rest reach out to external services because there is no other way: to read the DNS records of somebody else’s domain or measure a server’s response time, the request has to come from our side. These tools store nothing.

Network and domains — 7 tools

Everything about the domain, the server and how they answer the outside world.

• DNS records — A, AAAA, MX, NS, TXT, CNAME, SOA, SRV, PTR and CAA. The first place to look when a site “does not open” or email stops flowing.
• Domain WHOIS — registrar, creation date and expiry date. The age of a domain is especially telling: it explains a great deal about why a site is not ranking yet.
• Site hosting — whose servers the site runs on and in which country. Useful when checking a contractor or a competitor.
• Response time — DNS, connection, TLS and TTFB as separate figures.
• Redirect checker — the whole 301 and 302 chain to the final address. It doubles as a link unshortener: it reveals where a bit.ly really leads without you opening it.
• Port checker — whether a port is open from outside, distinguishing “closed” from “filtered by a firewall”.
• Internet speed test — download, upload, ping and jitter with a speedometer.

IP address and anonymity — 4 tools

• My IP — your address, provider and city at a glance.
• IP information — country, city, provider, ASN and timezone for any address.
• Anonymity check — what sites see about you: proxy headers, membership of Tor or a hosting network, a real IP leak through WebRTC, a timezone mismatch. The most common finding is WebRTC: it exposes the real address around the VPN.
• IP calculator — subnets, masks, CIDR ranges.

SEO and marketing — 9 tools

The largest group. These are the tools we use ourselves on client projects every day.

• Indexability check — answers “why is this page not in Google”: robots.txt rules for your exact URL, the noindex meta tag, the X-Robots-Tag header, the canonical and redirects.
• Meta tags and Open Graph — what the page tags say and whether they fit the limits.
• Meta tag generator — build title, description, canonical, OG and Twitter Card with a live snippet preview.
• Schema.org generator — JSON-LD structured data: LocalBusiness, Article, Product, FAQPage, breadcrumbs.
• robots.txt generator — with presets for WordPress, OpenCart and online stores.
• sitemap.xml generator — crawls the site through its links and returns a ready file.
• 301 redirect generator — rules for .htaccess and Nginx with infinite-loop checks.
• Website speed audit — TTFB, weight, compression, caching, image formats and a 0–100 score with a fix list.
• UTM link builder — a correct link for ads and newsletters, with presets.

Security and access — 5 tools

• SSL check — issuer, dates and days remaining. An expired certificate switches the site off for every visitor at once.
• Security headers — HSTS, CSP, X-Frame-Options, X-Content-Type-Options.
• Malware scanner — malicious code signatures, hidden iframes, miners, plus the availability of system files such as .env and .git/config.
• Password generator — any length and complexity you need.
• .htpasswd generator — password-protect a section or a staging site at server level.

Email — 6 tools

The group people underestimate until their letters start disappearing into spam.

• SPF check — with every tag explained and typical mistakes flagged.
• DKIM lookup — the signing key by selector.
• DMARC check — the domain policy: p, rua, ruf.
• Blacklist check — whether an IP is in Spamhaus, SpamCop and other databases.
• SPF generator — build a correct record for your sending services.
• DMARC generator — a policy tuned to your needs, from soft to strict.

Text and images — 4 tools

• WebP converter — compression and resizing right in the browser, up to 20 files at a time. Transparency is preserved for WebP and PNG.
• Character and word counter — with title and description length checks and reading time.
• QR code generator — for a link, text, Wi-Fi or a business card.
• QR code reader — from a photo, screenshot or camera. It shows where a code leads before you follow it.

For developers — 6 tools

• Developer utilities — MD5, SHA-1, SHA-2, SHA-3, RIPEMD-160, Whirlpool, Base64, ROT-13, Unix time, ASCII and HEX in one place.
• JSON formatter — with validation and the exact position of an error: line and character.
• Text comparison — by line or by word, with a change count.
• Cron decoder — what an expression means in plain words.
• Punycode converter — IDN domains both ways.
• Transliteration — Ukrainian Latin script by the official standard.

Documents and bank details — 2 tools

Ukrainian specifics you will not find in international tool sets.

• Tax ID and EDRPOU check — the code checksum, and for a tax ID also the date of birth and gender encoded in the number itself.
• IBAN check — validation by the international MOD-97 algorithm with a breakdown into bank code and account number.

Where to start if this is your first visit

The most useful sequence for a site owner looks like this:

1. Indexability check on your homepage — confirm the site is open to Google at all.
2. Speed audit — find the technical brakes visible from outside.
3. Malware scan — it will also reveal whether system files are publicly reachable.
4. SPF and DMARC — if you email your customers.
5. SSL — simply to know when your certificate expires.

That is five minutes of work, and it usually surfaces two or three real problems.

The questions we get most often

Is it really all free? Yes, with no limit on the number of checks and no registration. We build these tools for ourselves and our clients, not as a separate product.

Do you store my data? No. Some tools send nothing to a server at all — everything is computed in your browser. The rest run the request at the moment you press the button and log nothing.

Can I use them on sites I do not own? Yes, every check uses publicly available information — the same thing any visitor or search crawler sees. The one limit we set deliberately is on the port checker: no more than 15 ports per request, so the tool does not turn into a network scanner.

If the checks made it clear that something needs fixing but not what exactly, get in touch — we will look and tell you specifically. And if you would rather work it out yourself, start with our guide on how to get to the top of Google.