Proofsource vs Prefer (2026): A pay-per-question meter against a full-stack pitch
Proofsource starts at $9/mo, priced per question and engine, with error bars on every number. Prefer lists $59 to $79 for Starter and a Promptwatch-style feature list. Which one to trust.
Proofsource is a narrow, carefully documented tracker that bills you per question and per engine. Prefer sells a complete AI visibility stack on paper, but its own pages disagree with themselves often enough that we would not budget for it before seeing a logged-in workspace.
Proofsource wins on price transparency and statistics. Prefer wins on the length of its feature list. A procurement team should care more about which claims it can check. We read Proofsource's pricing page, llms.txt and AI Traffic feature page on 20 October 2026. Prefer's figures come from our catalog entry, which was sourced from tryprefer.com/facts.json and the live pricing card in late August 2026.
Side by side
| Proofsource | Prefer | Promptwatch | |
|---|---|---|---|
| Company | Grovio Labs, Inc. (Delaware) | Kocoa Technologies Private Limited, Mumbai | Promptwatch B.V., Amsterdam |
| Entry price | From $9/mo (5 weekly questions on ChatGPT) | Starter $79/mo, $59 yearly (live card showed $59 with $79 struck) | Explore free; Essential $95/mo |
| How you pay | $28/mo daily or $7/mo weekly per brand, plus per question per engine | Flat tiers: Starter, Growth $249, Scale $499 | Flat tiers by prompts, responses and seats |
| Trial | 2 days, 25 questions, 4 engines, no card | Free trial, no card, 14-day money-back | Free Explore plan; 7-day trial on Essential |
| Self-serve engines | ChatGPT, Perplexity, Claude, Google AI Overviews | Five per facts.json; homepage FAQ also names Copilot and Grok | All tracked LLMs on Essential |
| AI crawler data | Cloudflare zone or log drain, bots verified | Module named Agent Analytics on the homepage | Agent Analytics from Professional, seven CDN integrations plus custom HTTP |
| Conversions | GA4, set up by the Proofsource team on a call | GSC + GA on Starter | Visitor analytics via script or GTM |
| Content | Drafted fixes with approval, WordPress publishing | 15 AI articles a month on Starter | 5 AEO articles on Essential, 15 on Professional |
| Managed option | From $1,000/mo | $2,500/mo | Not published |
How Proofsource works
Every brand pays a cadence fee, $28 a month for daily checks or $7 for weekly, plus a price per question on each engine you switch on. Claude costs more per question because, the pricing page says, it searches the web and reads about 14k words per answer. Questions beyond 50 per brand get 20% off, and yearly billing charges 10 months. Team seats are unlimited and there are no overages.
Mention rate, share of voice and position come with a 95% Wilson confidence interval, where most trackers print one percentage and let you assume it is exact.
The AI Traffic view connects a Cloudflare zone or takes access logs as a log drain. It counts requests from GPTBot, ClaudeBot, PerplexityBot and others, verifies each against published IP ranges or reverse DNS, and sorts pages into crawled and cited, crawled but never cited, or cited but rarely crawled. That is the right question to ask of crawler data.
Things to check before paying:
- Only four engines are self-serve. Google AI Mode, Gemini, Copilot, Grok, DeepSeek and Meta AI need a sales call or Managed, even though the pricing table lists 10 engines for every brand.
- GA4 is wired up by Proofsource staff on a call. It is not a connector you add yourself.
- The $9 entry is 5 weekly questions on one engine. That is a demo, not a trend.
How Prefer works
Prefer's homepage describes prompt tracking, citation analysis, a module called Agent Analytics, Content Agents, an Action Center, a Query Fanout Estimator and edge tracking through Cloudflare, Vercel, Fastly and Akamai. CMS targets named in its FAQ are Webflow, WordPress, Shopify, Framer, Ghost and Contentful. Starter lists 50 prompts, five engines, 15 AI articles, three competitors, one project, two seats and MCP access.
Those are Promptwatch's product names, nearly in Promptwatch's order, and the homepage carries the same 4.7 G2 figure Promptwatch publishes. We allege nothing about the code. The point is that a marketing page interchangeable with another vendor's feature sheet tells you little about the product behind it.
Other details from our catalog entry belong in a procurement note. Testimonials give names and job titles but no employers. The logo strip is labeled as early-access participants, not customers. The engine count shifts between five, "all 6" on Growth and a homepage FAQ that adds Copilot and Grok. Managed at $2,500 a month carries a written 90-day citation-visibility guarantee, but its case study measures Google Search Console clicks, which the same page says are not AI citations.
Who should pick which
Pick Proofsource if you are a small brand or agency that wants to pay only for the questions you track, values confidence intervals, and already runs on Cloudflare. Budget for more than the $9 sticker once you add daily cadence and 25 or 50 questions.
Pick Prefer only after a live demo of a real workspace, and ask in writing which homepage modules exist today.
The Promptwatch option
Both tools point at the same chain: was the page crawled, was it cited, did the visit convert. Promptwatch runs that chain self-serve. Agent Analytics reads crawler logs from Cloudflare, AWS CloudFront, Fastly, Vercel, Netlify, Akamai, Google Cloud CDN or custom HTTP, with the crawl-to-citation path and crawl errors. Visitor analytics installs with a script or GTM template, no setup call needed. Citation analytics breaks out pages, Reddit and YouTube.
Professional at $245 a month includes 150 prompts, 18,000 responses, 25M crawler logs, 1M visitor events and 15 AEO articles, with daily refresh. Against Proofsource, the deciding factor is coverage: more engines without a sales call and more crawler sources. Against Prefer, it is the product those feature names come from, with 1,840+ brands and agencies on it.
Verdict
Proofsource is the honest pick of this pair: published pricing, careful statistics and the right crawl-to-citation idea. Prefer's public pages do not yet let a buyer verify the product behind them. For the whole loop without sales calls, start with Promptwatch Professional, and keep Proofsource in mind as a cheap, statistically careful second opinion.
FAQ
Is Proofsource the same company as ProveSource?
No. Proofsource (proofsource.co) is an AI visibility tool from Grovio Labs, Inc. ProveSource is an unrelated social-proof popup tool.
Why does Prefer look so much like Promptwatch?
Its homepage reuses Promptwatch's product names and G2 figure. The public pages do not show an independent product behind that copy.
Which is cheaper for daily tracking?
It depends on question count. Proofsource's total rises with every question and engine on top of the $28 daily fee. Promptwatch Essential is a flat $95 a month for 50 prompts across all tracked LLMs. Try the free Explore plan at promptwatch.com.