"Cheapest" Isn't One Number
Ask which AI generation API is cheapest and the honest answer is: it depends on what you generate, how much, and how predictable you need the bill to be. Three platforms dominate the image-and-video generation space in 2026 — OpenAI (the model maker), fal.ai (serverless GPU inference), and LinkModel (a discounted commercial-model gateway) — and they bill on three completely different philosophies. Compare only the sticker rate and you'll pick wrong.
This guide normalizes the real costs, surfaces the fees that don't appear on pricing pages, and says plainly which route wins for which job.
Three Billing Philosophies
| Platform | Bills by | Price behavior | You carry |
|---|---|---|---|
| OpenAI direct | Tokens (per model) | List price; Batch API halves it | Token math + latest-model access |
| fal.ai | GPU-second or per output | Varies with load, cold starts, tier | Cost modeling per request |
| LinkModel | Per request | Fixed, shown before the call, up to 30% off official | Almost nothing — same code, lower rate |
OpenAI gives you the source model and a real bulk discount (Batch), but you own the token arithmetic. fal.ai gives you a huge open-source catalog and per-GPU-second flexibility, but your cost floats with GPU type, queue depth, and cold starts. LinkModel keeps the commercial models and their exact response format, applies a pre-negotiated markdown, and quotes the price before each request — trading fal's raw flexibility for predictability.
Image Generation, Compared
For OpenAI's own image model, direct is the baseline: GPT Image 2 runs about $0.05 per medium 1024px image on OpenAI's token pricing (halved again via Batch). fal.ai shines on open image models — Flux, SDXL, Seedream — from roughly $0.03 per image, and as low as fractions of a cent for the fastest open models, which is unbeatable for bulk, text-light work. LinkModel focuses on the premium commercial models (GPT Image 2, Gemini/Nano Banana image) at up to 30% below official.
The rule of thumb: open-weight bulk → fal.ai; premium commercial image at a discount → LinkModel; latest OpenAI model with Batch bulk → OpenAI direct. The full per-image math is in the GPT Image 2 pricing breakdown.
Video Generation, Compared
Video is where the numbers get dramatic. Normalized to one minute of 1080p, Artificial Analysis puts Seedance 2.0 around $9/min, Kling 3.0 Pro around $20/min, and Veo 3.1 around $24/min. On fal.ai, video is billed per output second — roughly $0.05/s for budget open models up to $0.40/s for premium — or per GPU-second if you self-deploy, with the same load-dependent variance as its image pricing. LinkModel offers the commercial video models (Seedance, Kling, Sora 2, Hailuo) at a fixed per-request price up to 30% below each provider's official rate.
For a single 4K hero clip, the model choice dominates the bill (pick Kling for native 4K). For thousands of social variations, per-unit cost and predictability dominate — see the full head-to-head in Seedance 2.0 vs Kling 3.0 and the access routes in the Seedance API guide. A broader video-model roundup lives in best AI video API.
The Fees That Aren't on the Pricing Page
Sticker price is where comparison starts, not ends. Independent trackers estimate hidden costs add ~20% across the industry. Specific ones to model:
- Cold starts and queue variance (fal.ai). Per-GPU-second billing means the same generation can cost noticeably more at peak load, and you pay for spin-up. Great when it's cheap; hard to forecast.
- Payment-processor overhead on small top-ups (fal.ai). Tiny prepaid top-ups get eaten by processing fees — community reports put this at 5–15%.
- Edit-fidelity billing (OpenAI images). Reference-image edits bill at high input fidelity you can't disable — iterative workflows can run 2–3x the headline per-image cost.
- Token-math error (OpenAI direct). Budgeting from the calculator instead of a real week of logged calls is how teams overshoot.
Fixed per-request pricing sidesteps most of these: with LinkModel the quoted price is the price, which is the quiet reason predictable billing often beats a lower-but-variable rate at month's end. The structural comparison is detailed in LinkModel vs fal.ai.
So What's Actually Cheapest?
There's no universal winner — there's a right tool per workload:
- Open-weight models, custom checkpoints, or self-hosting → fal.ai. Nothing beats it for Flux/SDXL/Wan bulk or bring-your-own-weights.
- The very latest OpenAI model, run in overnight batches → OpenAI direct with the Batch API.
- Commercial image and video models at a predictable, discounted price → LinkModel. Up to 30% below official, one API for 40+ models, fixed price per call, 99.95% SLA, and zero data retention by default.
For most teams shipping product features on top of premium generation models — GPT Image 2, Seedance, Kling, Sora — the combination of a real discount and a bill you can forecast is what makes LinkModel the default. For the complete cross-category rate card, see the AI API pricing comparison.
Try It on Your Own Numbers
The only budget that matters is yours. Sign up for LinkModel for a $1 starter credit, point your existing code at https://api.linkmodel.ai/api/v1, and compare your real per-call cost against your current provider — no card, no commitment. Or compare model outputs first in the Playground.