Keeper vs FlyFin: two AI deduction engines for freelancers, compared
Both link your bank accounts and let a model hunt write-offs year-round. They differ on what happens after the AI finishes.
Keeper and FlyFin solve the same problem with near-identical mechanics: connect bank and card accounts, let a model classify every transaction against deductible categories continuously, then file a return that is largely assembled before filing season opens. Both are AI-native, both are US-only, and both are built for 1099 income rather than W-2 salary.
The interesting divergence is what surrounds the model. Keeper leans on the deduction-finding itself as the product and reports users surfacing roughly 168 write-offs on average. FlyFin leans on the claim of near-total automation — it says its engine handles up to 95% of prep work — and puts licensed CPA review behind every return as the guarantee.
| Product | Best-rated source | Regions | Built on AI | HQ |
|---|---|---|---|---|
| Keeper | 4.8/5 Trustpilot | US | AI-native | San Francisco, US |
| FlyFin | 4.6/5 Apple App Store | US | AI-native | San Jose, US |
How each one's AI actually works
Keeper runs a GPT-4 model fine-tuned on US tax law. That fine-tuning matters for the part of the job that is not classification: an in-app assistant answers tax questions in the context of your own transactions, rather than answering generically. Ambiguous purchases are surfaced for a yes/no confirmation instead of being silently guessed.
FlyFin's engine is also GPT-4-based and purpose-built for tax questions. Its framing is throughput — automate the preparation work, then use CPAs as the accuracy backstop. Where Keeper sells you a tool that finds money, FlyFin sells you a finished return with professional review attached.
What the review record shows
Keeper is the stronger performer on the platforms where both appear. It holds 4.8 on Trustpilot across roughly 314 reviews and 4.8 on the Apple App Store, with reviewers repeatedly citing the deduction-finding and fast human support. FlyFin sits at 4.6 on the App Store, where reviewers credit the tracker with catching write-offs they had missed for years — but a recurring minority raise billing and support complaints.
Read the volumes as well as the scores. Keeper's iOS app has passed 750,000 downloads and FlyFin reports over 250,000 users, so both have a real base, but neither has the review depth of a mainstream filing product. Treat the scores as directional.
Where each one fits
If your situation is straightforward 1099 income and the value you want is finding deductions you would otherwise miss, Keeper's model plus its in-app assistant is the tighter fit, and its review record is the better of the two. If you would rather hand the whole return over and have a CPA sign off on the automation's output, FlyFin is built around that promise.
Neither is the right tool if you have moved past sole-proprietor simplicity. Once an S-corp election, payroll, or multi-entity structure is in play, the automation you need is different — that is Lettuce's territory, and worth comparing before committing.
The verdict
Frequently asked
- Is Keeper or FlyFin better for finding tax deductions?
- Both scan linked bank and card transactions continuously. Keeper reports users surfacing roughly 168 deductions on average and holds higher third-party ratings (4.8 on both Trustpilot and the App Store, versus FlyFin's 4.6 on the App Store), which makes it the safer default for deduction-finding specifically.
- Do Keeper and FlyFin both include a human tax professional?
- Yes, in different ways. Keeper hands the completed return to a human professional for review and e-filing on paid plans. FlyFin puts licensed CPA review behind every return as a core part of its offer.
- Can these tools file state as well as federal returns?
- Both are US filing products covering federal and state returns. Neither operates outside the United States, so freelancers elsewhere should look at the regional options instead.
Profiles referenced
Keeper
keepertax.comA GPT-4 model fine-tuned on tax law scans your bank transactions all year, finds the write-offs, and files the return with human review.
FlyFin
flyfin.taxClaims to automate 95% of freelancer tax prep with a purpose-built tax AI, then puts licensed CPAs behind every return.