Seedream 4.0vs.Nano Banana (Gemini 2.5 Flash Image)

Which one is better?

In our own test both are on par. Neither is in the arena. Neither has an API price.

Same task, the first image of each. The task with the biggest difference is preselected.

Seedream 4.0: Product photography, first image from the fixed test run — Seedream 4.031 out of 100

Nano Banana (Gemini 2.5 Flash Image): Product photography, first image from the fixed test run — Nano Banana (Gemini 2.5 Flash Image)77 out of 100

Result for “Product photography”:Nano Banana (Gemini 2.5 Flash Image) ahead

Prompt given to both modelsCreate a square premium product photograph of a brushed titanium wristwatch standing upright on dark green marble. The watch has a cream dial, thin black hands set to 10:10, twelve distinct hour markers, a realistic crown, and a dark brown leather strap. Soft window light from the left, controlled reflections, shallow depth of field, no text, no logo, no extra objects.

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 (Gemini 2.5 Flash Image): fal, aspect ratio 1:1, n=1, seed=provider random, Fal schema does not expose an output-resolution parameter; require square output of at least 1024px, estimated cost $0.039800, generated Nov 1, 2026, 8:51 PM. Source

Protocol gradually-image-comparison-v1. Prompt SHA 256: 985a75b38642a9f0e5e0c0e0c67f1b7f67780d42bd2168fa24e9a7a7a94b0da6

Seedream 4.0 image SHA 256: 81b5aa023fa252472878015448b5ee1cefcbc61844dd6cff98997685d7ab1511

Nano Banana (Gemini 2.5 Flash Image) image SHA 256: 69ecb842e42e25cf866919f9bfa573f08398a78d4fa46bca2f9c9c27996d80a7

Infographic

Seedream 4.0: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 12:25 PM. Source

Protocol gradually-image-comparison-v1. Prompt SHA 256: ed65cb4e6a51e2336f8b149ad4cbb16e020f07d527ad94362e719d2dcf91d94f

Seedream 4.0 image SHA 256: 63dcddf4bf7bb58ea0c67eea96f2c71834158568f29ed3b7f2523b56a91e6526

Nano Banana (Gemini 2.5 Flash Image) image SHA 256: d12f93429b044d541a8ea71a1fd135f89343ff6efaefafe679e9e28699ee54cf

Product photography

Seedream 4.0: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 12:24 PM. Source

Protocol gradually-image-comparison-v1. Prompt SHA 256: c67fd71e91304458a2feef5c91efa8677260fab0c0099a29a2c52cb579f5b2f3

Seedream 4.0 image SHA 256: 1fbad61d03b05e6cd8523e76409983e86c11c74fca2fa1a14d20f07f0d801519

Nano Banana (Gemini 2.5 Flash Image) image SHA 256: afdcf628727069979bcc9797a18b283079f9cafb136d8fcbc118ae1fc5523a15

Typography and layout

Seedream 4.0: together, 1024x1024, n=1, seed=provider random, provider default steps, generated Aug 14, 2026, 2:01 PM. Source

Protocol gradually-image-comparison-v1. Prompt SHA 256: 2e012c3d14ee5dd02203a94f394ca80a5038cdebd6032b25a8b8a221f2255419

Seedream 4.0 image SHA 256: 029be40f71522352246ad0de0de2e6c1ed2e45608f59c4f0e1be87b4dc2353c1

Nano Banana (Gemini 2.5 Flash Image) image SHA 256: eeafdc566564b9398bc45b9e8cbaa7f4ca38a1b8795e198cd056c4bc47f72121

The numbers at a glance

Arena ratingfrom votes by users · higher is better

n/a

Seedream 4.0

not in the arena

n/a

Nano Banana (Gemini 2.5 Flash Image)

not in the arena

GraduallyBenchour own rating, 0 to 100 · higher is better

Seedream 4.0

Rank 51 of 74

Nano Banana (Gemini 2.5 Flash Image)

Rank 44 of 74

Price per imagedollars through the API · lower is better

n/a

Seedream 4.0

no API price

n/a

Nano Banana (Gemini 2.5 Flash Image)

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 (Gemini 2.5 Flash Image)

Subscription: n/a No plan in Germany names exactly this model.
Via API: No API price known. Access: API.
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 (Gemini 2.5 Flash Image)
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	54
GraduallyBench by task
Typography and layoutLegible text, hierarchy, and composition	36	58
Product photographyMaterials, reflections, and fine details	31	77
Character and detailAnatomy, clothing, and spatial consistency	40	54
InfographicNumbers, labels, and visual organization	69	27
API price
Per imagelower is better	n/a	n/a
100 images	n/a	n/a
Profile
Released	September 2025	Oct 2, 2025
Weightsopen means: runs locally	proprietary	unknown
Lifecycle	no notice	Active stable API ID; earliest announced shutdown date is March 15, 2027
Access	API, Web app	API
Parameters	not published	not published
Largest output	4K	not consistently published
Plans in Germanynaming exactly this model	16	n/a

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 (Gemini 2.5 Flash Image) model source, status 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 (Gemini 2.5 Flash Image) from the same arena and category. Older model versions are not used as substitutes.

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More matchups

Compare Seedream 4.0 and Nano Banana (Gemini 2.5 Flash Image) with other important image models.

View the complete image model comparison

Same prompt, two images

The numbers at a glance

Seedream 4.0

Nano Banana (Gemini 2.5 Flash Image)

All data side by side

Arena ratings by category

No shared arena score in the stored snapshot

Compare another matchup

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