Cometly vs Fathom Analytics in 2026: B2B Pipeline Attribution vs Privacy-First Traffic Analytics
One connects a paid ad click to closed-won ARR in the CRM, sold only through a sales call. The other is a $15-a-month, cookieless traffic counter with no consent banner and no CRM in sight.
Cometly
Fathom Analytics- Fathom publishes a single price starting at $15/month with a 7-day free trial. Cometly discloses no pricing anywhere and requires a sales call to get a quote based on website session volume.
- Cometly connects a specific ad campaign to closed-won ARR using real CRM deal values across a 90-day cohort. Fathom has no CRM integration or revenue attribution feature at all; it reports traffic, referrers, and conversion events.
- Fathom collects no cookies and no personal data, so no GDPR, CCPA, or PECR consent banner is required. Cometly uses both pixel and server-side tracking built around identifying and attributing individual sessions to ad campaigns.
- Cometly auto-detects named AI traffic sources: ChatGPT, Gemini, Grok, and Google AI Overviews. Fathom has no built-in AI traffic detection as a named feature.
- Every Fathom plan includes API access and at least 50 sites, making it practical for agencies managing many client properties at one predictable cost. Cometly restricts its API to the Enterprise tier only.
- Fathom retains data forever on every plan with no expiry. Cometly does not publish a data retention policy, since its core value is the attribution model rather than raw historical traffic data.
Cometly and Fathom Analytics both live under the "analytics" label, but they were built to answer completely different questions for completely different buyers. Cometly exists to tell a B2B SaaS marketing team whether a specific ad campaign eventually became closed-won revenue, tracked against real CRM deal values over a 90-day cohort. Fathom exists to tell any website owner how many people visited, where they came from, and what they clicked, without collecting a single cookie or forcing a consent banner on anyone. One requires a sales call and discloses no pricing; the other has a single public price and a 7-day trial. This comparison is really about whether your problem is proving ad ROI on a long B2B sales cycle, or just wanting clean, private traffic numbers without a Google Analytics implementation.
The tools at a glance
Cometly
B2B SaaS ad attribution that connects every campaign dollar to pipeline created and closed-won ARR
Cometly tracks the complete customer journey from first ad impression to closed-won ARR, calculating return against actual CRM deal values rather than platform-reported conversions. The 90-day cohort view exists specifically because B2B SaaS sales cycles are longer than the attribution windows most ad platforms default to, so a demo booked today might not close for months and needs to be traced back to the original campaign anyway.
A server-side Conversion API runs alongside the standard pixel, recovering an estimated 15 to 30 percent more conversion events than pixel tracking alone by sending data directly to ad platform APIs rather than depending on browser signals that ad blockers strip out. Cometly also auto-detects traffic from ChatGPT, Gemini, Grok, and Google AI Overviews, showing those as named channels alongside Google Ads and LinkedIn Ads with the same pipeline metrics applied.
Access is the trade-off. There is no public pricing, billing is based on website session volume, and getting a number requires a sales call. MCP integration for Claude, CRM and warehouse sync with Snowflake and BigQuery, and the Cometly API are all locked to Enterprise, so evaluating the product on a tight timeline is genuinely harder than with a self-serve tool.
| Feature | Core Usage-based, contact for pricing | Enterprise Custom |
|---|---|---|
| Pricing model | Based on website sessions | Custom |
| Server-side tracking (Conversion API) | ✓ | ✓ |
| Multi-touch attribution | ✓ | ✓ |
| Ask AI | ✓ | ✓ |
| 70+ integrations | ✓ | ✓ |
| CRM and warehouse sync | ✗ | ✓ |
| MCP integration | ✗ | ✓ |
| Cometly API | ✗ | ✓ |
Fathom Analytics
Simple, GDPR-compliant web analytics with cookieless tracking, forever data retention, and no consent banners
Fathom is a privacy-first web analytics platform used on over a million websites, including properties for IBM, GitHub, and Tailwind CSS. It collects no cookies and processes no personal data, which means no consent banner is required under GDPR, CCPA, or PECR. Setup is a single script tag that works with any CMS or framework, and the dashboard covers real-time and historical visitor counts, top pages, referrers, countries, device types, and conversion events.
Every plan retains data forever, a deliberate contrast to GA4's rolling data windows, and every plan also includes API access and at least 50 sites, which makes Fathom practical for agencies managing multiple client properties at one predictable monthly cost rather than paying per site. Event and ecommerce tracking are included on every plan without needing a tag manager for the most common events.
Fathom is bootstrapped and independently owned with no venture capital involved, and the founders have been public about keeping the product simple rather than expanding into advertising technology. The limitation is scope: there is no product analytics, no user journey tracking, no heatmaps, and no named AI traffic detection, since Fathom is purpose-built to answer "how much traffic, from where" rather than deeper behavioral or revenue questions.
| Feature | All plans From $15/mo |
|---|---|
| Pricing model | Based on monthly page views |
| Sites included | 50+ |
| Data retention | Forever |
| API access | ✓ |
| Ecommerce tracking | ✓ |
| No cookie banners required | ✓ |
| 7-day free trial | ✓ |
Head-to-head feature comparison
| Feature | Cometly | Fathom Analytics |
|---|---|---|
| Primary use case | B2B SaaS ad attribution, first touch to closed-won ARR | Privacy-first web traffic analytics |
| Pricing transparency | None (sales call required for a quote) | Full public pricing, one plan level |
| Starting price | Usage-based (session volume), custom quote | $15/month |
| CRM/pipeline revenue attribution | Yes (core feature, tied to actual CRM deal values) | No (no CRM integration or revenue attribution feature) |
| Cookieless / no consent banner required | No (relies on pixel and server-side session tracking) | Yes (no cookies, no personal data collected) |
| AI traffic source detection (named engines) | Yes (ChatGPT, Gemini, Grok, Google AI Overviews) | No named AI traffic detection feature |
| Server-side / Conversion API tracking | Yes (Conversion API, both tiers) | No (not a server-side ad conversion tool) |
| Data retention | Not publicly specified | Forever, on every plan |
| Multi-site / agency support | Not a named feature | Yes (50+ sites included on every plan) |
| API access | Enterprise only | Yes (included on every plan) |
| Free trial | Not clearly offered | Yes (7 days) |
Considering AI visibility monitoring alongside Cometly or Fathom Analytics?
Cometly names ChatGPT, Gemini, Grok, and Google AI Overviews as attribution channels once someone clicks through from one of them, but Fathom has no equivalent feature and neither tool has visibility into how often your brand is mentioned inside an AI answer where no click ever happens. AI Peekaboo tracks brand citations across ChatGPT, Gemini, Perplexity, and Google AI Overviews at the prompt level, with a read/write API on every plan from $50 a month and white-label reporting for agencies already building client dashboards around Fathom or GA4 traffic data.
Read the AI Peekaboo review →Which should you choose?
CometlyFathom AnalyticsFathom AnalyticsCometlyFathom AnalyticsCometlyFathom AnalyticsThese tools are not really in competition, because they answer different questions for different budgets. Cometly is expensive to evaluate and built for one narrow, high-stakes question: did a specific B2B SaaS ad campaign turn into closed-won revenue. Fathom is cheap to evaluate and built for a much broader, simpler question: how much traffic is coming to any website, from where, without collecting personal data. A B2B SaaS company could plausibly run both, Fathom for clean baseline traffic reporting across marketing sites and Cometly for the harder pipeline-to-ARR question on paid campaigns specifically.
Bottom line
Book the Cometly demo with your monthly session volume ready if you cannot currently trace a specific campaign to a closed-won deal 60 to 90 days later. Start the Fathom trial if you want private, cookieless traffic analytics with no consent banner and a price you can see before signing up. Agencies managing many client sites should look hard at Fathom's 50-site minimum and forever retention before assuming they need anything more complex.
Frequently asked questions
Can Fathom Analytics replace Cometly for ad attribution?
No. Fathom reports traffic, referrers, device data, and conversion events, but it has no CRM integration and no revenue attribution model. Cometly is purpose-built to connect a specific ad campaign to closed-won ARR using real CRM deal values, which is a fundamentally different job than Fathom is built to do.
Is Cometly more expensive than Fathom Analytics?
Almost certainly, though Cometly does not publish pricing so an exact comparison is impossible. Fathom starts at $15/month with a fixed page-view-based price. Cometly bills on website session volume after a sales call, and its target buyer (B2B SaaS companies running paid ad campaigns) typically has a much higher budget than Fathom's self-serve pricing implies.
Does Fathom Analytics require a cookie consent banner?
No. Fathom collects no cookies and processes no personal data, so consent banners required under GDPR, CCPA, or PECR do not apply. Cometly, by contrast, uses pixel and server-side tracking designed to identify and attribute individual sessions, which is a different privacy posture entirely.
Does Cometly track traffic from AI tools like ChatGPT the way some privacy analytics tools do?
Yes, and this is one of Cometly's more distinctive features: it auto-detects and names ChatGPT, Gemini, Grok, and Google AI Overviews as attribution channels, applying the same pipeline and closed-won ARR metrics to them as any paid channel. Fathom has no equivalent named AI traffic detection feature.
Is Fathom Analytics good for agencies managing multiple client sites?
Yes, deliberately so. Every Fathom plan includes at least 50 sites and full API access at one predictable monthly cost, with additional site packs available for $10/month per 50. Cometly has no comparable multi-site or agency-focused pricing structure, since it is built around a single B2B SaaS company's ad spend and CRM.