Head-to-head
Keitaro vs Fospha
On paper these are both attribution tools. In practice Keitaro and Fospha answer different questions, and the reason it is hard to choose is that you probably do not need both on the table. Keitaro is a self-hosted tracker that reads which click, campaign, offer and lander converted. Fospha is a measurement platform that models which channel earned the credit for your whole store's revenue. One follows the click. The other follows the money.
By Marcus Flynn, tracking and attribution editor. Updated 28 September 2026.
Pick Keitaro if you buy paid traffic to offers and landers you route yourself and want deep click-level tracking, offer rotation and conversion feedback to Meta, TikTok and Google on a self-hosted tracker with a flat license from EUR 40 a month; pick Fospha if you are a retail brand spending six figures a month on your own store and want modeled, channel-level measurement of real revenue instead of pixels.
Quick answer
Keitaro is our top pick for most people. It is real, and it is one of the longest-standing self-hosted trackers in affiliate marketing, not a fly-by-night tool. Keitaro, from Apliteni, installs on your own Linux server, routes your ad clicks through it, and tracks clicks, cost, conversions and ROI while distributing traffic across landing pages and offers by GEO, device, browser and schedule and syncing conversions back to Meta, TikTok and Google. You will regret buying it only if you are not ready to run a VPS, expected it to track out of the box, or spend too little for the licence plus server upkeep to beat a cheap cloud tracker. For a serious media buyer at real volume who wants to own their data and stop paying per event, it is a genuine long-term home.
- Keitaro. Best for High-volume affiliate and media buyers who want a proven self-hosted tracker with hands-on support. From €40/mo.
- Fospha. Best for Retail and ecommerce brands spending six figures a month that want modeled measurement instead of pixels. From $1,500/mo.
Side by side
| Tool | Server‑side CAPI | Anti‑fraud kit | Self‑hosted | From |
|---|---|---|---|---|
| 5. Keitaro | Meta, TikTok, Google | Bot filtering built in | ✓ | €40/mo |
| 13. Fospha | –Unknown | –Unknown | –Unknown | $1,500/mo |
Keitaro: pros and cons
What works
- The licence does not climb with your clicks. Individual plans run EUR 40 to 104 a month billed yearly, with no per-event or per-click cap, so a campaign that suddenly does volume never trips an overage fee the way a cloud tracker can.
- You own the data. Keitaro runs on your own VPS, so your click and conversion data lives on hardware you control, with retention you set rather than a cloud plan's limits.
- It is a deep media-buying tracker, not a light attribution layer: streams and filters on GEO, device, browser, operator and schedule, offer and lander rotation, A/B testing, server-to-server postbacks, conversion sync to Meta, TikTok and Google, more than 35 parameters and fast multi-level reports.
- It is established and well supported. Keitaro's own site cites more than 4,000 businesses, long-term reviews describe years of continuous use, and support is the single most repeated piece of praise, at 4.5 out of 5 on Trustpilot.
What to watch
- You run the server. The docs require a clean VPS on CentOS 9 or 10 Stream with KVM, 20 GB of SSD and 4 GB of RAM or more, and the domains, SSL, backups, updates and security are yours to keep up. That weighs most on a non-technical or low-volume buyer; a media buyer who already runs a VPS will find it a fair trade for owning the data.
- There is no free trial. You buy a licence to use it, so you cannot run a real campaign through it for free first, though a public live demo lets you click around the interface. That puts the burden on you to be sure before you pay.
- When the server or the support chain fails, it costs money. The sharpest reviews describe 502 errors on server-to-server conversion tracking and slow resolution. Those usually trace to an under-provisioned VPS rather than the tracker itself, but on a self-hosted tool part of your uptime is your own responsibility.
- It carries reputation baggage. Security researchers have documented Keitaro's traffic-distribution system being abused in malware and cloaking campaigns, so some strict ad networks view the toolset warily. That is about criminal misuse of a general routing tool rather than honest tracking, but it is a reason to keep your redirects clean and your use compliant.
Fospha: pros and cons
What works
- Non-pixel measurement that credits the upper-funnel channels last-click misses. Because it models from 100% of your real store revenue rather than platform-reported conversions, it surfaces contribution from prospecting social, YouTube, TikTok and display that GA4 and in-platform ROAS tend to undercount.
- Well reviewed by the brands that use it: 4.5 out of 5 from 51 G2 reviews, with recurring praise for ease of use, support and finally seeing channel value that click tracking hid.
- Measures marketplaces, not just your own site. On Pro and up it models the halo from paid media into Amazon and TikTok Shop sales, which pixel-based DTC dashboards structurally cannot see.
- Daily outputs with forecasting, not a quarterly report. The model retrains daily and Beam projects returns at different spend levels, so it works as a budget-allocation tool and not just a scorecard.
- Fast, transparent onboarding: most clients are live in under 28 days with 24 months of historical data, and Fospha runs a glass-box model you can interrogate layer by layer rather than a black box.
What to watch
- No free trial and no self-serve sign-up. You book a demo and commit to paid onboarding before you see it work on your own data, so the only way to validate it is to buy it. Ask for two or three references from brands like yours before you do.
- The floor is high: Lite is $1,500 a month and is built for brands already spending $100k to $500k a month on media. Below roughly $100k a month of spend it is overkill, and its own pricing tiers say so.
- Pro adds a percentage of your media spend on top of a $2,000 base, and Fospha does not publish that percentage, so the true all-in cost is opaque until you talk to sales.
- It reports modeled estimates, not deterministic user-level tracking, so its numbers will not match Meta, GA4 or Shopify. That is the point of a mix model, but it means your team needs a governance rule for which source to trust, and Fospha itself says the ad-level view is directional, not creative-level truth.
- Reporting flexibility is a common gripe: G2 reviewers mention limited report editing, filtering and segmentation friction, and manual data work to get some cuts of the data. It is a measurement layer, not a build-your-own BI tool.
The real differences
Two tools, two different questions
The hard part of this comparison is that Keitaro and Fospha are not really rivals. Both get filed under attribution, and both promise to tell you what your marketing is doing, but they answer different questions and they answer them for different people.
Keitaro answers: which click, source, offer and lander converted. It sits in the traffic path on your own server, stamps every click, distributes and rotates the visitor across offers and landing pages by GEO, device, browser and schedule, and reads the conversion back through a server-to-server postback. The unit is the click, the truth is deterministic, and the job is buying paid traffic to offers and landers you route.
Fospha answers a different question: which channel deserves credit for the revenue your store actually booked. It does not sit in the click path and it does not fire a pixel. It takes your real store revenue, your spend across every channel, and runs a daily marketing mix model that distributes credit for that revenue. The unit is the channel, the truth is modeled, and the job is allocating budget across Meta, TikTok, YouTube, display and marketplaces for a brand you own.
Deterministic tracking versus modeled measurement
This is the split under everything else. Keitaro is deterministic: a click carries an ID, the ID comes back on the conversion, and the tracker reports it as fact. That is exactly what you want when you are running an offer and need to know which placement, source and lander paid. It is click-level, it reconciles with your affiliate network, and it does not guess.
Fospha is modeled. A marketing mix model does not follow individual users. It explains total revenue as a function of spend across channels over time, and hands back a credit split. That is what lets it value prospecting social, YouTube and upper-funnel display that last-click and pixels routinely undercount. The vendor puts it plainly: it moved away from pixel-based tracking to give every channel, including the ones that generate demand, the credit it deserves. The cost is that its numbers are estimates. They will not match Meta, GA4 or Shopify to the cent, and Fospha says its ad-level view is directional, not creative-level truth. A team running Fospha needs a rule for which source wins when they disagree.
Neither approach is better in the abstract. Deterministic click tracking is right for routed offers where the click is the whole story. Modeled measurement is right for an owned brand buying many channels, where no single pixel sees the full journey.
Who owns the offer, and who owns the server
Keitaro is software you host. Its own docs require a clean Linux VPS on CentOS 9 or 10 Stream with KVM, 20 GB of SSD and 4 GB of RAM or more, and from there the tracking domains, SSL, backups, updates and uptime are yours to keep. The payoff is control: your click and conversion data lives on your own server, with retention you set rather than a cloud plan's limits, and a flat license that does not climb with your traffic. Keitaro states the trade plainly, calling self-hosting the choice for maximum control, privacy and unlimited growth. That fits a media buyer who values owning the data and pushing volume without a bill that grows.
Fospha is the opposite in every dimension. It is fully managed cloud, there is nothing to host, and onboarding takes most brands under 28 days with 24 months of history loaded. But it is built around your own store: it needs your revenue data, your ad accounts and your analytics, which only a brand that owns its checkout can supply. An affiliate routing traffic to someone else's offer has nothing for Fospha to model.
Conversions back, and fraud filtering
Here the tools stop mirroring each other. Keitaro carries the media-buyer kit: traffic distribution by GEO, device, browser, operator and schedule, offer and lander rotation, A/B testing, more than 35 parameters and fast multi-level reports. It syncs conversions server-side to Meta, TikTok and Google on top of the server-to-server postbacks it uses for the networks you route, so a buyer optimizing against platform events has that feedback built in, and it ships bot filtering as part of the tracker. The honest caveats sit on the infrastructure: the sharpest reviews describe 502 errors on server-to-server conversion tracking, which usually trace to an under-provisioned VPS rather than the tracker itself, so budget a server that can carry your volume.
Fospha carries what a measurement platform needs instead: daily model retraining, forecasting through its Beam tool, post-purchase attribution, and marketplace measurement that models the halo from paid media into Amazon and TikTok Shop sales. A pixel-based dashboard structurally cannot see that, and neither can a click tracker. What Fospha is not is a conversion API pipe: it does not feed clean, server-side conversions back to the ad platforms. If posting owned, multi-touch sales back to Meta and Google is central to how you buy, Keitaro does that job and Fospha does not.
Who each one is for
Keitaro is for the media buyer or affiliate pushing real click volume to offers and landers they route, who is comfortable running a server, wants deterministic click tracking with conversion feedback to the ad platforms, and prefers a flat license and data they own. Below meaningful volume it is more machinery than the job needs, and if you will not run infrastructure it is ruled out on that alone. There is no free trial either, only a public live demo, so the burden is on you to be sure before you pay.
Fospha is for the retail or ecommerce brand already spending six figures a month on its own store, that wants modeled, channel-level measurement instead of pixels, and can commit to a $1,500-a-month floor with no trial. Below roughly $100,000 a month of spend, a clean pixel plus CAPI does most of the job for far less, and Fospha's own pricing tiers say so.
One caveat covers both. Neither tool fixes a weak offer, a broken pixel setup or a low conversion rate. Keitaro makes the click clearer; Fospha makes the channel mix clearer. Neither makes the funnel better.
What each one costs
Keitaro charges a flat license that ignores your click count, billed yearly. Individual plans are EUR 40 (Starter), EUR 72 (Advanced) and EUR 104 (Expert) a month, with Team and Enterprise higher, and Keitaro lists discounts for paying six or twelve months up front. There is no per-event or per-click cap, so a campaign that suddenly does volume never trips an overage. There is also no free trial, only a public live demo, and the Linux VPS you host it on is a separate ongoing cost on top of the license.
Fospha starts an order of magnitude higher and is priced for the spend it measures. Lite is $1,500 a month and is built for brands already spending $100,000 to $500,000 a month on media. Pro is $2,000 a month plus an undisclosed percentage of your media spend, for brands up to $1,000,000 a month. Enterprise is quoted. There is no free trial and no self-serve tier, so the only way to see it work on your own data is to buy the onboarding.
The two do not cross the way two trackers would, because they are not sized for the same buyer. Keitaro's whole appeal is a low, flat fee on a box you own while your traffic climbs. Fospha's floor assumes you are already spending six figures a month and want that spend measured, not the clicks routed. If Keitaro looks cheap next to Fospha, that is the clearest sign these tools are not aimed at the same operator.
Prices read from each vendor's own pricing page, current as of 27 September 2026.
Our pick
Keitaro
It is real, and it is one of the longest-standing self-hosted trackers in affiliate marketing, not a fly-by-night tool. Keitaro, from Apliteni, installs on your own Linux server, routes your ad clicks through it, and tracks clicks, cost, conversions and ROI while distributing traffic across landing pages and offers by GEO, device, browser and schedule and syncing conversions back to Meta, TikTok and Google. You will regret buying it only if you are not ready to run a VPS, expected it to track out of the box, or spend too little for the licence plus server upkeep to beat a cheap cloud tracker. For a serious media buyer at real volume who wants to own their data and stop paying per event, it is a genuine long-term home.
Frequently asked questions
Keitaro or Fospha: which should I pick?
Are Keitaro and Fospha actually competitors?
Is Keitaro or Fospha cheaper?
Does Fospha track clicks the way Keitaro does?
Which one sends conversions back to Meta and Google?
Sources
Other sources
4 discussions and reviews read for this page. Quotes are excerpts; open a link to read the original in context.
- [keitaro-home] Keitaro - Your Ad Performance Tracker
- [keitaro-selfhost] Keitaro - Your Ad Performance Tracker
- [fospha-home] Fospha | The Measurement Operating System for Retail Commerce
- [fospha-price] Fospha pricing
How we compared these
We do not run paid campaigns through either tool. We read each vendor's own documentation and pricing, verify every number against the source, and weigh the long-term reports of operators who run them at real spend. The full rubric is on the methodology page.