GPT Image 2 vs Nano Banana Pro
The cheaper model changes as the resolution rises
At 1K, GPT Image 2 costs 300 credits and Nano Banana Pro costs 750. At 2K it is 500 against 750. At 4K it is 800 against 750, and the order flips. Nano Banana Pro charges one flat price across 1K, 2K and 4K; GPT Image 2 charges a ladder whose top rung is unreachable on four of its eleven recognised aspect ratios. Both models run in production on Doitong, so the credit figures below are the amounts actually deducted — API list prices are a different number from what an end user without an API key pays.
How to decide between them
Fix the resolution first
At 1K it is 300 against 750. At 2K, 500 against 750. At 4K, 800 against 750. There is no resolution where the two cost the same.
Check the aspect ratio ceiling on the GPT Image 2 side
1:1 caps at 2K; auto, 5:4 and 4:5 cap at 1K. A request above the ceiling is downscaled silently, and billed at the delivered tier.
Multiply by your batch size
100 images: $9.90 to $20.10 on GPT Image 2 at 1K, $24.70 to $50.30 on Nano Banana Pro at any resolution.
Both models, every tier, in credits and dollars
| Model and resolution | Credits | @ $0.67 / 1,000 | @ $0.40 / 1,000 | @ $0.33 / 1,000 |
|---|---|---|---|---|
| GPT Image 2 — 1K | 300 | $0.201 | $0.120 | $0.099 |
| GPT Image 2 — 2K | 500 | $0.335 | $0.200 | $0.165 |
| GPT Image 2 — 4K | 800 | $0.536 | $0.320 | $0.264 |
| Nano Banana Pro — 1K | 750 | $0.503 | $0.300 | $0.247 |
| Nano Banana Pro — 2K | 750 | $0.503 | $0.300 | $0.247 |
| Nano Banana Pro — 4K | 750 | $0.503 | $0.300 | $0.247 |
| Model and resolution | Credits | @ $0.67 / 1,000 | @ $0.40 / 1,000 | @ $0.33 / 1,000 |
|---|---|---|---|---|
| GPT Image 2 — 1K | 30,000 | $20.10 | $12.00 | $9.90 |
| GPT Image 2 — 2K | 50,000 | $33.50 | $20.00 | $16.50 |
| GPT Image 2 — 4K | 80,000 | $53.60 | $32.00 | $26.40 |
| Nano Banana Pro — any resolution | 75,000 | $50.30 | $30.00 | $24.70 |
| Aspect ratio | Highest resolution available |
|---|---|
| 9:16, 21:9, 16:9, 4:3, 3:2, 3:4, 2:3 | 4K |
| 1:1 | 2K — 4K not available |
| 5:4 and 4:5 | 1K |
| auto (and any unrecognised value) | 1K |
| Pack | Price | Per 1,000 credits |
|---|---|---|
| 30,000 credits | $19.99 | $0.67 |
| 100,000 credits | $39.99 | $0.40 |
| 300,000 credits | $99.99 | $0.33 |
Nano Banana Pro supports 1K, 2K and 4K at the same 750-credit price. We do not publish its per-aspect-ratio limits.
The comparison, number by number
Credit cost, side by side
Nano Banana Pro charges 750 credits per image at 1K, 2K and 4K — resolution does not move the price. GPT Image 2 charges by tier: 300 credits at 1K, 500 at 2K, 800 at 4K. The comparison therefore flips as resolution rises. At 1K, GPT Image 2 costs 300 credits and Nano Banana Pro costs 750. At 2K it is 500 against 750, a difference of 250 credits. At 4K it is 800 against 750, so Nano Banana Pro is 50 credits cheaper. There is no resolution at which the two models cost the same amount.
What those credits cost in dollars
Credits are bought in three packs: 30,000 credits for $19.99, 100,000 for $39.99, and 300,000 for $99.99. That works out to $0.67, $0.40 and $0.33 per 1,000 credits, so the same generation can cost $0.67 versus $0.33 per 1,000 depending on which pack it was drawn from. One GPT Image 2 image at 1K costs $0.201, $0.120 or $0.099. At 2K it costs $0.335, $0.200 or $0.165, and at 4K $0.536, $0.320 or $0.264. Nano Banana Pro costs $0.503, $0.300 or $0.247 per image at every resolution it supports.
The same comparison at batch scale
Per-image cents are hard to feel, so here is the same arithmetic at 100 images. GPT Image 2 at 1K: $20.10, $12.00 or $9.90 depending on the pack. At 2K: $33.50, $20.00 or $16.50. At 4K: $53.60, $32.00 or $26.40. Nano Banana Pro at any resolution: $50.30, $30.00 or $24.70. On the largest pack a hundred 1K images cost $9.90 on GPT Image 2 and $24.70 on Nano Banana Pro; a hundred 4K images cost $26.40 and $24.70.
GPT Image 2 caps resolution per aspect ratio
GPT Image 2 does not offer the full 1K/2K/4K ladder on every aspect ratio. At 1:1 the ceiling is 2K. At 5:4 and 4:5 the ceiling is 1K, as it is when the aspect ratio is left as auto. The full ladder up to 4K is available on 9:16, 21:9, 16:9, 4:3, 3:2, 3:4 and 2:3. Two behaviours matter before you plan a batch. A request above the ceiling is silently clamped down rather than rejected — you get an image, just a smaller one than you asked for. And any aspect ratio outside the recognised list (auto, 1:1, 5:4, 9:16, 21:9, 16:9, 4:3, 3:2, 4:5, 3:4, 2:3) is normalised to auto, which carries the 1K ceiling.
GPT Image 2 has no 4K tier at 1:1
This is the cleanest hard limit in the comparison. GPT Image 2's ceiling at 1:1 is 2K, so a square 4K image is not something it produces: ask for it and you get 2K back, billed at 500 credits rather than 800. The same applies more sharply at 5:4 and 4:5, which cap at 1K. Nano Banana Pro prices 1K, 2K and 4K identically at 750 credits, but we do not publish its per-aspect-ratio limits — so if your deliverable is a square at maximum resolution, verify the output dimensions on a single test render before committing a batch.
When to pick which, and what these numbers do not cover
Pick GPT Image 2 when the output is 1K or 2K on one of the ratios that reach the full ladder: at 1K you pay 300 credits against 750, the largest cost gap between these two models. Pick Nano Banana Pro when the target is 4K on a ratio GPT Image 2 caps below it, or when a batch mixes ratios you have not audited — a flat 750 means neither resolution nor ratio can change what you pay. Everything above is price and resolution behaviour; it is not a quality comparison. We do not publish prompt-adherence scores or blind preference tests for either model. Nano Banana Pro accepts up to 14 reference images; treat 14 as an upper bound, not a per-request guarantee.
GPT Image 2 vs Nano Banana Pro — questions with numbers in the answer
Which is cheaper, GPT Image 2 or Nano Banana Pro?
It depends on resolution, and the answer reverses. At 1K on Doitong, GPT Image 2 costs 300 credits and Nano Banana Pro costs 750. At 2K it is 500 against 750. At 4K it is 800 against 750, so Nano Banana Pro is 50 credits cheaper. There is no resolution where the two cost the same.
Can GPT Image 2 generate a 4K square image?
No. GPT Image 2's ceiling at 1:1 is 2K, so 4K is not available on square output. A 4K request at 1:1 is silently clamped to 2K rather than rejected, and billed at the 2K price of 500 credits. The seven ratios that do reach 4K are 9:16, 21:9, 16:9, 4:3, 3:2, 3:4 and 2:3.
How much does Nano Banana Pro cost at 4K?
750 credits on Doitong, the same as at 1K and 2K — the price is flat across all three resolutions it supports. In dollars that is $0.503, $0.300 or $0.247 per image depending on whether the credits came from the 30,000, 100,000 or 300,000 pack. Resolution has no effect on what a Nano Banana Pro generation costs.
What happens if I ask GPT Image 2 for a resolution above its ceiling?
The request is silently downgraded to the highest resolution allowed for that aspect ratio, not rejected. A 4K request at 1:1 returns 2K; a 4K or 2K request at 5:4, 4:5 or auto returns 1K. Price is computed from the same normalised aspect ratio as delivery, so the tier you are billed for can never be higher than the tier you actually received.
Which aspect ratios reach 4K on GPT Image 2?
9:16, 21:9, 16:9, 4:3, 3:2, 3:4 and 2:3 have the full ladder up to 4K. The 1:1 ratio stops at 2K. The 5:4 and 4:5 ratios stop at 1K, as does auto. Any ratio outside the recognised list is normalised to auto, which means it also stops at 1K.
What does one image cost in dollars rather than credits?
Credits come in three packs on Doitong: 30,000 for $19.99, 100,000 for $39.99 and 300,000 for $99.99, which is $0.67, $0.40 and $0.33 per 1,000 credits. So a GPT Image 2 image at 1K costs $0.201, $0.120 or $0.099, and at 4K $0.536, $0.320 or $0.264. Nano Banana Pro costs $0.503, $0.300 or $0.247 at any resolution.
What does 100 images cost on each model?
On GPT Image 2 at 1K, 100 images is 30,000 credits: $20.10, $12.00 or $9.90 depending on the pack. At 2K it is 50,000 credits: $33.50, $20.00 or $16.50. At 4K it is 80,000 credits: $53.60, $32.00 or $26.40. On Nano Banana Pro, 100 images is 75,000 credits at any resolution: $50.30, $30.00 or $24.70.
Which model produces better image quality?
We publish credit cost, resolution tiers and aspect-ratio ceilings, because those can be read directly from the running system. We do not publish prompt-adherence scores or blind preference tests for either model, so there is no quality ranking here to cite.
Other model pricing pages on Doitong
300 / 500 / 800 against a flat 750
GPT Image 2 is cheaper at 1K and 2K. Nano Banana Pro is 50 credits cheaper at 4K, and its price never moves.
Compare them on Doitong