Promptmonitor Review 2026: Two Companies Share This Name, and the Cheapest Six Engines We Have Found

Search “prompt monitor” and the first result is promptmonitor.io. The third is promptmonitor.ai, a different company selling the same thing. Both track brand mentions across AI models. One publishes its prices; the other does not. If you have been told to evaluate Promptmonitor, the first job is establishing which one.

This review covers promptmonitor.io, which at $29 a month for six engines is the cheapest six-engine entry plan in our verified catalogue. It also publishes prompts, refresh cadence and total responses on the same card, which is rare and generous, and those three numbers do not reconcile with each other.

Disclosure: EchoWi competes with Promptmonitor. Every price, allowance, cadence and engine name below was read from promptmonitor.io’s own pricing page on 7 August 2026, and every derived figure shows its arithmetic. The .ai observations come from that company’s own homepage on the same day.

The short version

1. Two companies share the name. promptmonitor.io and promptmonitor.ai are unrelated and both sell AI brand monitoring.
2. $29 a month for six engines, the cheapest six-engine entry plan we have verified.
3. Responses divided by prompts is 90 on both lower tiers, a constant the page lets you derive.
4. Those 90 cannot be six engines at the stated cadence. The two tiers imply ten engines and three.
5. Growth is cheaper per response than Pro, so the ladder stops paying at the middle tier.

First, which Promptmonitor

We are not suggesting anything improper. Two companies picked adjacent domains in a young category, which happens. But it matters commercially: a shortlist that says “Promptmonitor” without a domain is ambiguous, and the two differ on the thing you would compare first, which is whether you can see the price at all.

Everything below is the .io one.

What it costs, verified

The engine list, quoted exactly: “ChatGPT (Open AI), Claude, Gemini, DeepSeek, Grok, Perplexity”. Six, on every tier including the $29 one. A 7-day free trial covers the paid plans.

Two things about that table before the arithmetic.

Every price is a discount. All three tiers show a struck-through higher number beside them. We have no way to know whether $49, $66 and $219 were ever charged, and a permanent sale is a common pattern in this market. We record what the page showed us.

Six engines at $29 is the floor of our catalogue. Rank Prompt also sells six on its entry plan, at $470 a year, which is $39.17 a month and annual-only. Nightwatch sells four at €79. Athena HQ sells eight, at $295. Nobody we have verified sells six for less than this.

The constant the page lets you derive

Divide responses by prompts:

Ninety, near enough, three times. That is a real disclosure and very few vendors in this market make it possible. It is the same thing that made Nightwatch’s thirty and Siftly’s sampling derivable, and it is more than most competitors publish.

Ninety responses per prompt per month is also a genuinely useful number. Across six engines that is fifteen observations per engine per month, which is enough to notice a large move on a single prompt and not enough to certify a small one. For a mention rate near 30%, fifteen observations carry a 95% confidence interval of roughly plus or minus 23 points, and the arithmetic behind that is the same one we apply to ourselves.

The three numbers that do not reconcile

Now take the cadence at face value and see what the response counts imply.

Starter, twice weekly, is about 8.7 refreshes a month. 25 prompts × 8.7 = 218 prompt refreshes. To reach 2,250 responses, each refresh would have to produce 10.3 responses.

Growth, daily, is about 30.4 refreshes a month. 50 prompts × 30.4 = 1,522 prompt refreshes. To reach 4,500 responses, each refresh would have to produce 3.0 responses.

The page names six engines on both plans. One tier’s numbers imply ten, the other’s imply three.

They cannot both be six engines at the stated cadence, so at least one of three things is not what a buyer would assume: the refresh cadence is not what the word suggests, the engine coverage per refresh is not all six, or “responses” counts something other than one engine answering one prompt. The page does not say which, and we are not going to guess.

To be fair, and this matters: most vendors in this comparison publish so little that no such contradiction is possible. You cannot catch an inconsistency in numbers nobody printed. Promptmonitor published three figures where the norm is one, and the cost of that openness is that the arithmetic can be checked. We would rather review a vendor that publishes three numbers that disagree than one that publishes none.

Where the ladder stops paying

Cost per response collected:

Growth is the cheapest tier per response, and Pro costs about 6% more per response than the tier below it. Going from $39 to $129 triples the prompt count and slightly worsens the unit price.

That is the same shape we found at Rank Prompt, where the discount stops at the Agency tier, and the opposite of Nightwatch, where it improves all the way up. The buying instruction is the same in every case: work out the unit price before you climb, because the ladder is not always a discount.

Set against the wider catalogue, $0.0087 a response is second cheapest overall, behind Siftly at $0.0055 on its top tier and ahead of Athena HQ at $0.082 by roughly a factor of nine.

The agency plan is unusual

“Free to pitch clients”, unlimited prompts, daily refresh, with revenue sharing and a sales email rather than a checkout.

We could not verify what the revenue share is, and it is not published. But the shape is worth naming, because it is different from every other agency plan in this comparison: Surfeo charges a base plus a fee per client, Rank Prompt scales by brand count, and Nightwatch bundles unlimited seats into a fixed tier. Promptmonitor is offering the tool for nothing during the pitch and taking a cut afterwards.

For a small agency with no budget and a prospect to win, that is a real option. It also means the vendor’s incentive is tied to your close rate rather than your seat count, which cuts both ways and is worth reading the contract for.

Where Promptmonitor is the right call

You want the widest engine coverage for the least money and you are tracking a small prompt set. Six engines including Claude, Grok and DeepSeek at $29 is the cheapest coverage we have verified that comes with a stated prompt allowance: Rankscale names ten engines from $20 and attaches no allowance to that price. DeepSeek in particular is rare below Enterprise anywhere else in the catalogue.

Take Growth at $39 rather than Starter unless the twice-weekly cadence genuinely suits you: it doubles the prompts, moves to daily, and is the cheapest tier per response on the whole card.

Where it is the wrong call

You need to know exactly what you are buying. The three published numbers do not reconcile, and until they do, you cannot tell whether ninety responses means fifteen per engine or something else entirely. Ask before you buy, and ask in writing.

It is also the wrong call if procurement needs a named, established vendor. The operator is Stackdirectory LLC, the pricing runs on a permanent discount, and a second company holds a nearly identical domain. None of that makes the product bad; all of it makes the paperwork harder.

What we could not verify

• How the 90 responses per prompt are distributed across the six engines and across the month.
• Which of the three published figures to trust when they disagree.
• What the agency revenue share is.
• Whether the struck-through prices were ever the list price.
• Any relationship, or absence of one, between promptmonitor.io and promptmonitor.ai. We observed two sites and did not contact either.
• What happens when a monthly response allowance runs out mid-month.

Promptmonitor versus the alternatives

Against the funded platforms, this is a different kind of purchase: a small, cheap, broad-coverage tracker with a published price, competing with tools that cost ten times more and often publish less.

Against the other cheap tools, the decision is coverage versus clarity. Promptmonitor gives you the most engines per dollar in our catalogue. Rank Prompt gives you six engines too, with a credit rule that is fully explained and an annual commitment. Siftly gives you cheaper responses at the top of its ladder but starts at three engines.

And whichever you pick, our own measurements this month say the same thing about all of them: how many runs you need is a property of your category, not of the vendor’s brochure. Ninety responses a month per prompt is generous in a settled category and thin in a churning one.

Every price here sits alongside the rest, each read from the vendor’s own page, in our comparison of every tool we verified.

Common Questions About Promptmonitor

How much does Promptmonitor cost?

$29 a month for Starter, $39 for Growth and $129 for Pro, each shown discounted from $49, $66 and $219 respectively. There is an agency plan that is free while pitching clients, with revenue sharing, and a 7-day free trial on the paid tiers.

Which AI engines does Promptmonitor track?

Six, on every plan including the cheapest, quoted from its page: ChatGPT, Claude, Gemini, DeepSeek, Grok and Perplexity. At $29 that is the cheapest six-engine entry plan among the tools we have catalogued.

How often does Promptmonitor check each prompt?

Twice weekly on Starter and daily on Growth and Pro. The page also publishes total monthly responses, and dividing those by the prompt count gives about 90 responses per prompt per month on every tier. Those two figures do not reconcile at six engines: Starter’s implies about ten responses per refresh and Growth’s about three.

Are there two companies called Promptmonitor?

Yes. promptmonitor.io and promptmonitor.ai are separate companies both selling AI brand monitoring, ranking first and third for the search “prompt monitor”. This review covers promptmonitor.io. The .ai site names three models and publishes no prices on its homepage.

Is Promptmonitor good value?

On coverage per dollar it is second: six engines from $29, behind Rankscale, which names ten from $20 and states no prompt allowance there. On clarity, it is mid-table, because its three published allowance figures disagree with each other. Take Growth rather than Starter, which at $0.0087 per response is the cheapest tier on the card and cheaper per response than Pro.

Is Pro worth the jump from Growth?

Not for the unit price. Growth works out at $0.0087 per response and Pro at $0.0092, so Pro is about 6% more expensive per response. Buy Pro for the prompt count, which triples from 50 to 150, not for economies of scale that are not there.