Paste any vendor's pricing page and see every promise they make, quoted word for word — with how much evidence a careful buyer would want for each one before signing. Free to check, no account needed.
A startup from fort mill, the United States, founded by David A. Thompson.
This page is designed to help you find out whether PromiseProof is good and if it is the right choice for you.
The promises on a sales page are the ones you'll want to hold a vendor to later — and they're the ones nobody writes down before signing.
Six months into the contract, the argument is about what was said. And the page has quietly changed.
PromiseProof reads a vendor's pricing or product page and pulls out every consequential promise: guarantees, performance figures, superlatives, breadth claims. Each one is quoted word for word and rated by how much substantiation a careful buyer would want if they asked for it.
If the wording isn't on the page, it isn't in your result. No summarising, no paraphrasing, no inference about what a vendor "probably means".
That's a legal conclusion, and PromiseProof doesn't make legal conclusions. It tells you what was promised, in their words, on the day you looked — and what a prudent buyer would ask to see.
Procurement teams, RFP and software-selection leads, consultants running vendor shortlists, and due-diligence practitioners. Not for vendors policing their own copy — that's a different product with a different incentive.
We fetch only the page you name, and only if its robots.txt permits it. We keep the address that was checked and what was found. Nothing about you.
Free to check. No account, no email address. Paid detail from $3.
Listed in
Claim extraction
Every consequential promise quoted verbatim — never paraphrased or inferred
Substantiation rating
Each claim rated by how much evidence a careful buyer would need to see
Single-page scope
Reads only the URL you name, nothing else on the domain
robots.txt respected
Skips any page the site's robots.txt disallows
No account required
No signup, no email address, nothing stored about you
Dated record
Keeps the address checked and what was found, on the day you looked
Next.js and TypeScript on Vercel, Supabase Postgres, and the Vercel AI SDK for the extraction step. Fetching respects robots.txt and reads only the single page you name.
It extracts claims rather than generating them. If a sentence isn't on the page, it isn't in your result — no summarising, no paraphrasing, no inference about what a vendor "probably means".
Then it does the part nobody else does: it rates each promise by how much substantiation a careful buyer would want before paying. "99.9% uptime" and "trusted by teams everywhere" are both marketing copy, but only one of them is a number someone could be held to.
And it deliberately stops short of a verdict. It never concludes a vendor is dishonest — that's a legal conclusion, and PromiseProof doesn't make legal conclusions. It tells you what was promised, in their words.
Page-monitoring tools tell you that a vendor's page changed. Competitive- intelligence tools tell you what a rival is saying, so your sales team can counter it.
Neither answers the question a buyer actually has before signing: of everything on this page, which promises would I want evidence for?
PromiseProof is built for the buyer's side of the table, not the seller's. It also runs with no account and no email address, so you can check a vendor without creating a record that you were looking at them.
KnightByrd built an evidence tool that reads a company's published claims and checks whether the sources cited beside them can actually carry the weight.
We ran it on our own website before running it on anyone else, and published the findings it returned against us. That felt like the only defensible way to launch a tool that judges other people's claims.
PromiseProof is the buyer's version of that idea. Six months into a contract the argument is always about what was said — and the page has quietly changed since. This writes down what was promised, on the day you looked.
People who evaluate vendors for a living: procurement teams, RFP and software- selection leads, management consultants running vendor shortlists, and due-diligence practitioners.
Anyone about to sign a contract on the strength of a pricing page.
Explicitly not built for vendors to police their own copy — that's a different product with a different incentive.
We have collected here some useful links to help you find out if PromiseProof is good.
Check the traffic stats of PromiseProof on SimilarWeb. The key metrics to look for are: monthly visits, average visit duration, pages per visit, and traffic by country. Moreoever, check the traffic sources. For example "Direct" traffic is a good sign.
Check the "Domain Rating" of PromiseProof on Ahrefs. The domain rating is a measure of the strength of a website's backlink profile on a scale from 0 to 100. It shows the strength of PromiseProof's backlink profile compared to the other websites. In most cases a domain rating of 60+ is considered good and 70+ is considered very good.
Check the "Domain Authority" of PromiseProof on MOZ. A website's domain authority (DA) is a search engine ranking score that predicts how well a website will rank on search engine result pages (SERPs). It is based on a 100-point logarithmic scale, with higher scores corresponding to a greater likelihood of ranking. This is another useful metric to check if a website is good.
The latest comments about PromiseProof on Reddit. This can help you find out how popualr the product is and what people think about it.
Do you know an article comparing PromiseProof to other products?
Suggest a link to a post with product alternatives.
Is PromiseProof good? This is an informative page that will help you find out. Moreover, you can review and discuss PromiseProof here. The primary details have been verified within the last quarter. So they could be considered up to date. If you think we are missing something, please use the means on this page to comment or suggest changes. All reviews and comments are highly encouranged and appreciated as they help everyone in the community to make an informed choice. Please always be kind and objective when evaluating a product and sharing your opinion.
