How much does it cost to run an AI image web app? Real numbers from a 5-month test (May–Oct 2026)
Last verified:
- 2026-10-22: Added model unit prices and masked billing evidence.
A roughly five-month test of an AI image web app (May 11–October 20, 2026) cost $8.61 in model API usage on fal.ai — 105 billed images in September–October at $0.03–$0.15 per image, plus $4.23 of model experiments in May — and KRW 29,682 in Naver search ads over 14 days (11,759 impressions, 72 clicks, about KRW 412 per click). $0 in paid charges was observed for hosting (Vercel Hobby) and database (Supabase Free): Vercel listed no invoices, and Supabase issued six $0 invoices. Total prepaid out of pocket was $10 + KRW 35,000; June–August had no API usage, and Vercel Hobby is for non-commercial use, so this is a test-cost record, not an operating budget.
The recorded costs
Section titled “The recorded costs”| Item | Observed value | Evidence coverage | Interpretation |
|---|---|---|---|
| fal model consumption | $8.61 | May 1–October 20 snapshot, UTC | Account-wide usage, including training and model experiments |
| fal credit purchase | $10.00 | One May 11 receipt | Not added to consumption as another expense |
| fal credit balance | $1.39 | October 20 screen | Rounded display of remaining prepaid credit |
| Naver ad consumption | KRW 29,682 | BizMoney summary for September 21–October 20 | Displayed VAT-inclusive total; reconciliation gap below |
| Naver credit purchases | KRW 35,000 | September 26 and October 9 | Prepaid funds, separate from ad consumption |
| Vercel Hobby | No invoices listed | Captured October 20 invoice list | No paid charges observed in this capture |
| Supabase Free | Six invoices at $0.00 | Issued May 11, then June 11–October 11 | Both list pages rechecked October 22 |
USD and KRW remain separate. The evidence does not include the card’s actual KRW charge, exchange rate, or currency-conversion fees.
fal usage by month
Section titled “fal usage by month”| Period | Usage USD |
|---|---|
| May 2026 | 4.2311 |
| June | 0.0000 |
| July | 0.0000 |
| August | 0.0000 |
| September | 2.4310 |
| October 1–20, at collection time | 1.9502 |
| Total | 8.6123 |
Each month’s CSV net_amount was summed separately; the combined export reconciles to $8.61 but uses weekly buckets that can cross month boundaries. May includes training and experiments, and June–August showed no usage; averaging all months would not describe an active service.
Cost per image by model (fal.ai, account usage table)
Section titled “Cost per image by model (fal.ai, account usage table)”Image-billed models list per-image prices; PuLID and training retain their megapixel and step billing units.
| Model endpoint | Unit price | Quantity used | Cost | Month |
|---|---|---|---|---|
| fal-ai/nano-banana/edit | $0.0398 / image | 92 images | $3.66 | Sep 43 · Oct 49 |
| fal-ai/nano-banana-pro/edit | $0.15 / image | 2 images | $0.30 | Sep |
| fal-ai/flux-pro/kontext | $0.04 / image | 7 images | $0.28 | Sep |
| fal-ai/nano-banana | $0.0398 / image | 2 images | $0.08 | Sep |
| fal-ai/bytedance/seedream/v4/edit | $0.03 / image | 2 images | $0.06 | Sep |
| fal-ai/flux-pulid | $0.0333 / megapixel | 67 MP | $2.23 | May |
| fal-ai/flux-lora-fast-training | $0.02 / step | 100 steps | $2.00 | May |
| Total | $8.61 |
September–October: 105 billed images for $4.38, an average of $0.042 per image. Unit prices are what the account was charged at the time, rather than current list prices; check fal.ai pricing before planning.
Advertising cost and response
Section titled “Advertising cost and response”The performance CSV covers September 28–October 19. Its fourteen days from September 28 through October 11 total 11,759 impressions and 72 clicks; the October 12–19 rows are all zero. The click-through rate is 72 / 11,759 × 100, or about 0.61%.
That CSV has no cost column. Costs were checked separately against a BizMoney screen queried for September 21–October 20 and an export whose consumption rows are dated September 28–October 11.
The BizMoney screen total (KRW 29,682) differs from the sum of its daily rows (KRW 29,674) by KRW 8 and from purchases minus balance (KRW 29,683) by KRW 1; the files give no rounding rule, so the screen total is used.
Separating funding, consumption, and invoices
Section titled “Separating funding, consumption, and invoices”The $10 fal receipt funded prepaid credits; September’s $2.43 of usage was offset by prepaid credit, leaving $0.00 due. That zero additional bill does not make the model usage free.
Naver’s KRW 35,000 in prepaid funds is separate from the KRW 29,682 consumed. No promotion benefit is deducted: the program offers a non-refundable coupon convertible to BizMoney, but issuance and use are unverified. Official Naver notice
Conditions behind the small bill and excluded costs
Section titled “Conditions behind the small bill and excluded costs”This was a small test with inactive months. Vercel’s official Hobby scope is personal, non-commercial use, so this billing history is not a recipe for hosting a commercial service free. Commercial use requires an appropriate plan or a different host. Vercel Hobby documentation
The table covers model APIs, hosting, database service, and advertising. It does not assemble all development and AI coding subscriptions, labor, domains, office costs, business setup, payment fees, taxes, refunds, or regeneration costs. It also does not estimate throughput at scale or profit per customer.
Screenshot evidence and source coverage
Section titled “Screenshot evidence and source coverage”
The screenshots were saved on October 20, 2026. The evidence consists of the author’s retained monthly CSVs, invoices, receipts, Naver performance CSV, and BizMoney workbook. Full originals contain account or billing identifiers and are kept private. The first Supabase invoice was additionally checked on October 22; that does not extend the usage or advertising data cutoff beyond October 20.
A cost-record template to copy
Section titled “A cost-record template to copy”Copy this table to record purchases, consumption, balances, and the evidence for each service.
| Service | Usage period and timezone | Currency | Purchased or paid | Consumed | Balance | Evidence or gap |
|---|---|---|---|---|---|---|
| Enter service | Enter period | USD or KRW | Unverified | Unverified | Unverified | Receipt, CSV, capture date |
Leave missing inputs blank or unverified until checked. Broader launch materials are being prepared on the kit page.
FAQ
Does this mean a paid AI service costs $8.61 to run?
This is model usage for a small test account, including experiments. It excludes development subscriptions, labor, payment fees, and other business costs. There was no fal usage in June–August, so it is not a forecast for an active paid service.
Why does the receipt say $10 while usage is $8.61?
The $10 purchase funded prepaid credits. At the snapshot, usage rounded to $8.61 and the displayed credit balance was $1.39. Adding the purchase and consumption would count the same funds twice.
Can the Naver promotion be subtracted from ad spend?
The official program provides a non-refundable advertising coupon convertible to BizMoney. This record does not confirm issuance or use, so no promotional benefit has been deducted.
Do 72 ad clicks establish paid demand?
Clicks measure an advertising response. These files alone do not establish purchase intent or the number of paying customers. This is a cost record, not a profitability assessment.