in your browser
Logo and design brief
Logo and design brief
A questionnaire that turns into a brief for a logo, a brand, a label or a print job.
FREE TOOLS
Free tools
Checks and calculators that work at once and need no sign-up. The result is yours; send it to us only if you want help.
Brand & graphic design
in your browser
Logo file check
Logo file check
Whether your logo is vector, how large it prints sharp and how it looks on dark. The file is never uploaded.
Websites & online stores
on our server
Domain check
Domain check
Is the domain free, where does it point and who holds it — in seconds, no sign-up.
in your browser
Website brief
Website brief
Ten short questions and a written brief for a website or online store, ready to hand to any company.
Speed
on our server
Website speed test
Speed check
How fast your site loads on a phone and on a computer, and what slows it down — with Google PageSpeed, no sign-up.
Care & security
via public DNS
SPF, DKIM and DMARC check
SPF, DKIM and DMARC check
SPF, DKIM and DMARC for your domain: what is missing, what is wrong and the exact record that fixes it.
on our server
Who hosts this website
Who hosts this website
Which registrar holds the domain, where the site is hosted and who runs the mail.
on our server
SSL certificate check
SSL certificate check
When the certificate expires, who issued it and whether the chain is complete, with a reminder for your calendar.
Marketing & search
in your browser
ROAS calculator
ROAS calculator
Is your advertising making money? ROAS, break-even and the most you can pay for an order, from your own margin.
in your browser
Ad budget calculator
Ad budget calculator
A monthly and a daily budget worked out from your goal, your cost per click and your conversion rate.
on our server
AI visibility check
AI visibility check
Whether the ChatGPT, Claude and Perplexity crawlers can read your site and tell who you are.
on our server
Indexing check
Indexing check
noindex, robots.txt, canonical, the sitemap and redirects: the usual reasons Google leaves a page out.
Software & analytics
in your browser
Software brief
Software brief
Describe the users, the data and the steps, and get a brief split into phases.
in your browser
B2B ordering calculator
B2B ordering calculator
How many hours and how much money go on taking and re-keying phone, Viber and email orders.
in your browser
Product data check
Product data check
Duplicate codes, broken barcodes and prices stored as text in your stock export, checked in your browser.
TnB-SiteCheck
What our checks do
Our website checks identify themselves as TnB-SiteCheck and read only what a site shows every visitor and publishes for machines.
What we read
- One page: the address that was typed, and the redirects it leads to. The tracking check adds the label utm_source=tnb-tech-check to it.
- Google's public copy of the Tag Manager container the page names, from Google's server.
- robots.txt, the sitemap it names, and llms.txt.
- The certificate the site shows every browser.
- The domain's public DNS records, through the public resolvers of Cloudflare and Google.
- The share image, icons and manifest file a page names, and /favicon.ico, which every browser asks for on its own. We load them as an ordinary visit does: the site's robots.txt applies to them, but a server that only stores such files for the site is not asked separately.
We send one site at most 60 requests an hour, counting every visitor and every tool together. We never try passwords, forms or hidden addresses, and we never pretend to be another crawler.
QUESTIONS
What people ask
Why are the tools free?
Because they show how we work. The result is yours and you do not have to write to us; if you want help with it, the form is under every result.
Do you keep what I check?
We do not record who checked what. Website check results are kept briefly, under a key that does not reveal the address, so a repeat check opens at once; each tool says how long under its form. The calculators and file checks run in your browser. Without JavaScript your numbers and answers reach our server once so we can show the result, and we do not keep them.
Can I stop your checks reading my site?
Yes. Add two lines to robots.txt: "User-agent: TnB-SiteCheck" and "Disallow: /". The checks that read pages will stop and say why. The speed test will not, because our server never contacts your site for it: it sends the address to Google PageSpeed Insights, and Google loads the page.
Do you run penetration tests?
Not as a tool. We test a site's security only with your permission and an agreed scope: it is a service, not a button.