How PriceFern records prices and calculates costs
Where each price comes from, how it is dated and checked, and what the cost calculator assumes.
Published
Scope
AI search visibility tools: software that runs prompts through engines such as ChatGPT, Perplexity and Google AI Overviews and reports whether a brand appears. A product is listed if it is sold to businesses for this job and has a public pricing page. Plans priced only on request are listed as “not published”. Listing says nothing about quality.
How a price is captured
- A headless Chromium browser opens the pricing page (US locale, no account, no stored cookies), in each billing view the page offers.
- We save the page’s visible text, final URL, a SHA-256 fingerprint of its HTML and the capture time.
- Each number is copied from that saved text: price per billing period, currency, stated limits and paid add-ons.
- Anything the page doesn’t state is recorded as “not published”, never filled from sales calls, review sites or memory.
Prices are list prices in the vendor’s currency, as shown. Most pages don’t say whether tax is included. We don’t convert currencies or record discounts.
How often
Every pricing page is captured again at least once a month. Differences go on the changes page with both capture dates.
How the calculator works
Your workload (prompts, engines, check frequency, countries, brands, seats and billing period) is applied to every plan. Each plan gets one result.
| Result | Meaning |
|---|---|
| Fits | Plan price plus any add-ons the workload needs, per month and for 12 months. |
| Exceeds limit | Over a published limit, with no published add-on or overage rate. |
| Unsupported | The plan lacks an engine or check frequency the workload needs. |
| Unknown | Depends on something the vendor doesn’t publish. The calculator names it. |
| Price on request | The vendor publishes no price. |
Assumptions
- Usage follows each vendor’s own counting rule, recorded in its words. Some count prompts; others count every answer from every engine.
- A month is taken at its longest: 31 daily runs, 5 weekly runs. A plan that fits then fits every month.
- A plan with a fixed daily schedule is costed daily, because that is what it meters.
- A per-brand limit is checked against an even split of your prompts across brands.
- An engine the vendor names loosely (such as “Google AI”) gives an unknown result, not a guess.
- One country, one brand and one seat are assumed included unless the vendor says otherwise.
- Annual prices are per month as shown, or the annual total divided by 12.
- Currencies are never combined or compared.
Changes to this method
- : First version.