- Google lists 1K square output at $0.0336 for Flash-Lite Image and $0.067 for Flash Image; 2K and 4K output costs more.
- OpenAI GPT Image 2.5 bills image output tokens, with separate text/image input rates; per-image cost therefore changes with size and quality.
- Runway Gen-4 Image is credit-priced: the API docs equate 720p output to $0.05 and 1080p to $0.08 at $0.01 per credit.
- Grok Imagine Image 2.0 lists $0.04 per image in the overview; edits also bill the source image, and resolution/quality options affect the final rate.
| Tool | Price | Free tier | Status |
|---|---|---|---|
| Gemini 3.1 Flash Image (Nano Banana 2)Google | $0.067 per 1K image (output only) | No recurring API allowance confirmed in this comparison. | checked today |
| Gemini 3.1 Flash-Lite ImageGoogle | $0.0336 per 1K image (output only) | No recurring API allowance confirmed in this comparison. | checked today |
| GPT Image 2.5 (Sunburst / Flare)OpenAI | $30 per 1M image-output tokens; input billed separately | No recurring API allowance confirmed in this comparison. | checked today |
| Grok Imagine Image 2.0xAI | $0.04 per image (1K/2K listed) | No recurring API allowance confirmed in this comparison. | checked today |
| Runway Gen-4 Image (720p)Runway | $0.05 per 720p image (5 credits) | Paid API credits; developer credits listed at $0.01 each. | checked today |
Subscription vs. per-image API billing: which model fits your workflow
Image generation pricing divides sharply between subscription platforms (you pay a flat monthly fee for access and generate within a quota) and true metered APIs (you pay only for what you generate, per image or per token). Midjourney is the clearest subscription example: $30/month gets you a pool of Fast GPU hours, and at full utilization the effective per-image cost is very low — but if you only use 20% of your monthly Fast hours, your real per-image cost is 5x higher than the headline number implies. Per-image APIs like Gemini Flash Image have no fixed cost — they scale down to zero if you generate nothing — which makes them better suited to automated, bursty, or programmatic workflows where volume varies significantly month to month.
Resolution tiers and the cost multiplier most people miss
With token-billed image APIs like Gemini and GPT Image, resolution is not a free upgrade — it directly multiplies your cost because higher-resolution images require more output tokens to represent. Gemini 3.1 Flash Image charges roughly 1,120 image tokens at 1K–2K output resolution and 2,000 tokens at 4K, at a rate of $30 per million tokens. That means a 4K image costs almost double a 1K image from the same model. For applications where image quality matters less than throughput (product image variants, data augmentation, draft comps), generating at standard resolution is a straightforward way to cut image generation costs roughly in half without switching models.
The Midjourney "API" problem and why it matters for automation
Midjourney does not have an official public API. Any service marketing "Midjourney API access" is an unofficial third-party layer — typically a bot that interfaces with Midjourney's Discord interface on your behalf. This creates two real problems: reliability (unofficial wrappers can break silently when Midjourney changes its Discord interface) and cost (you're paying a markup on top of a Midjourney subscription you still need to hold). If programmatic automation is a hard requirement, Midjourney isn't a practical choice regardless of its quality reputation. The providers with real APIs — Gemini Flash Image, GPT Image, Flux — are the correct comparison set for automated pipelines.
Commercial use: don't assume it's included
Commercial usage rights for AI-generated images are not universally included at entry pricing tiers. Midjourney's terms require a Pro plan ($60/month) for companies with more than $1 million in annual gross revenue — below that threshold, the Standard tier allows commercial use, but the Basic tier ($10/month) does not grant full commercial rights for all use cases. For Gemini and other API-billed tools, commercial use is generally permitted on any paid tier. Before deploying AI-generated images in any monetized context — client work, product listings, social channels, licensed content — verify the commercial rights terms on the specific plan you're using, not the general terms for the platform.