Seedream 4.0vs.Nano Banana 2.1
Which one is better?
In our own test, Nano Banana 2.1 leads. Neither is in the arena. Neither has an API price.
Same prompt, two images
Same task, the first image of each. The task with the biggest difference is preselected.
Result for “Product photography”:Nano Banana 2.1 ahead
What the rating looks at: Materials, reflections, and fine details.
“Ahead”: better in all three rating rounds. “Slightly ahead”: a higher value, but not in every round.
Test protocol of the images
Both models receive the same archived prompt in exactly one request, and the first result counts. Files are normalized to 1,024 × 1,024 pixels without cropping. Provider resolution, randomness, quality tier and prompt processing can still differ. The images are a practical visual test, not a reconstruction of the arena configuration.
Character and detail
Seedream 4.0: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 12:24 PM. Source
Nano Banana 2.1: openrouter, aspect ratio 1:1, resolution 1K, n=1, seed=provider random, actual cost $0.036408, generated Nov 1, 2026, 9:40 PM. Source
Protocol gradually-image-comparison-v1. Prompt SHA 256: 985a75b38642a9f0e5e0c0e0c67f1b7f67780d42bd2168fa24e9a7a7a94b0da6
Seedream 4.0 image SHA 256: 81b5aa023fa252472878015448b5ee1cefcbc61844dd6cff98997685d7ab1511
Nano Banana 2.1 image SHA 256: f89e3f52678670058ce0e1e9b0b5b6ec084e25a212491b5025e76d7525fb8707
Infographic
Seedream 4.0: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 12:25 PM. Source
Nano Banana 2.1: openrouter, aspect ratio 1:1, resolution 1K, n=1, seed=provider random, actual cost $0.036560, generated Nov 1, 2026, 9:40 PM. Source
Protocol gradually-image-comparison-v1. Prompt SHA 256: ed65cb4e6a51e2336f8b149ad4cbb16e020f07d527ad94362e719d2dcf91d94f
Seedream 4.0 image SHA 256: 63dcddf4bf7bb58ea0c67eea96f2c71834158568f29ed3b7f2523b56a91e6526
Nano Banana 2.1 image SHA 256: ce5c4b7af2575ccf9964cfeea2e4f0bb75cdad21aea29c4201e693fa307e435b
Product photography
Seedream 4.0: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 12:24 PM. Source
Nano Banana 2.1: openrouter, aspect ratio 1:1, resolution 1K, n=1, seed=provider random, actual cost $0.036546, generated Nov 1, 2026, 9:39 PM. Source
Protocol gradually-image-comparison-v1. Prompt SHA 256: c67fd71e91304458a2feef5c91efa8677260fab0c0099a29a2c52cb579f5b2f3
Seedream 4.0 image SHA 256: 1fbad61d03b05e6cd8523e76409983e86c11c74fca2fa1a14d20f07f0d801519
Nano Banana 2.1 image SHA 256: 289b144f7d5348e9324d229e5508d5698c09035f2cbdea474845a84b852e859e
Typography and layout
Seedream 4.0: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 2:01 PM. Source
Nano Banana 2.1: openrouter, aspect ratio 1:1, resolution 1K, n=1, seed=provider random, actual cost $0.036497, generated Nov 1, 2026, 9:39 PM. Source
Protocol gradually-image-comparison-v1. Prompt SHA 256: 2e012c3d14ee5dd02203a94f394ca80a5038cdebd6032b25a8b8a221f2255419
Seedream 4.0 image SHA 256: 029be40f71522352246ad0de0de2e6c1ed2e45608f59c4f0e1be87b4dc2353c1
Nano Banana 2.1 image SHA 256: d27b58baa4115177a46fae2d71e258c5f4de9243fc66df93983ef6127df2f320
The numbers at a glance
Seedream 4.0
not in the arena
Nano Banana 2.1
not in the arena
Seedream 4.0
Rank 51 of 74
Nano Banana 2.1
Rank 11 of 74
Seedream 4.0
no API price
Nano Banana 2.1
no API price
Ranks among the 22 image models with an arena rating and the 74 with a GraduallyBench run; prices compared with 28 models with an API price.
Seedream 4.0
- Subscription
- No ByteDance subscription includes this model. Through other providers from €6.83 a month (Poe Basic, with limited points). 16 plans in Germany.
- Via API
- No API price known. Access: API, Web app.
Nano Banana 2.1
- Subscription
- At Google from €4.99 a month (Google AI Plus, with limited credits). Through other providers from €6.83 a month (Poe Basic, with limited points). 42 plans in Germany.
- Via API
- No API price known. Access: API, Web app.
- Weights
- unknown.
Subscriptions only count plans that name exactly this model. Subscription prices include VAT, API prices are in dollars.
GraduallyBench from Nov 1, 2026 · Subscription database from Sep 29, 2026 (34 days old)
All data side by side
The better value is bold. For ratings only when the gap is clear.
| Kennzahl | Seedream 4.0 | Nano Banana 2.1 |
|---|---|---|
| Ratings | ||
| Arena ratingfrom votes by users, higher is better | n/a | n/a |
| Arena rank | n/a | n/a |
| Arena votesmore votes, a safer rating | n/a | n/a |
| GraduallyBenchour own rating, 0 to 100 | 44 | 69 |
| GraduallyBench by task | ||
| Typography and layoutLegible text, hierarchy, and composition | 36 | 60 |
| Product photographyMaterials, reflections, and fine details | 31 | 80 |
| Character and detailAnatomy, clothing, and spatial consistency | 40 | 67 |
| InfographicNumbers, labels, and visual organization | 69 | 71 |
| API price | ||
| Per imagelower is better | n/a | n/a |
| 100 images | n/a | n/a |
| Profile | ||
| Released | September 2025 | Oct 6, 2026 |
| Weightsopen means: runs locally | proprietary | unknown |
| Access | API, Web app | API, Web app |
| Parameters | not published | not published |
| Largest output | 4K | not consistently published |
| Plans in Germanynaming exactly this model | 16 | 42 |
API prices for one image at 1,024 × 1,024 pixels according to Artificial Analysis.
Sources: Seedream 4.0 model source (verified Aug 15, 2026) · Nano Banana 2.1 model source (verified Nov 1, 2026)
Arena ratings by category
From blind votes on LMArena. “Ahead” means the lead is clear.
No shared arena score in the stored snapshot
The stored benchmark database contains no measurement for Seedream 4.0 and Nano Banana 2.1 from the same arena and category. Older model versions are not used as substitutes.
Compare another matchup
More matchups
Related image model comparisons
Compare Seedream 4.0 and Nano Banana 2.1 with other important image models.