Seedream 5.5 vs GPT Image 2.6: Quality, Price & Speed Tested

Seedream 5.5 (ByteDance, November 9, 2026) and GPT Image 2.6 (OpenAI) came out within days of each other, and both claim better text, better edits and better realism. We gave Seedream 5.5 and GPT Image 2.6 Sunburst, the top of OpenAI's three tiers, the same five prompts on ImagesArt at the same size and aspect ratio.

Short answer: GPT Image 2.6 Sunburst gave the better image in 4 of 5 tests: it follows "keep this exactly the same" more closely and adds nothing you did not ask for. Seedream 5.5 won on cost and speed: our seven Seedream images took about half the time and used about a third fewer credits, and both made real transparent PNGs. Use GPT Image 2.6 for final images where details matter, and Seedream 5.5 for drafts, volume and quick edits.

Try Seedream 5.5 →

Seedream 5.5 vs GPT Image 2.6 at a glance

GPT Image 2.6 Sunburst holds the maximum when you press Create and refunds what the image did not use. Our seven Sunburst images settled at 7 to 13 credits each. The Seedream images were made on our Seedream 5.5 page on November 13 and 14; the GPT Image 2.6 images on our GPT Image 2.6 page on November 15, with the same prompts and settings.

Test 1: realistic portrait with a chalkboard

Text to image, 3:4, 2K:

Cinematic close-up portrait of a 30-year-old woman with freckles and loose auburn hair, sitting by a rain-streaked café window at dusk, warm tungsten light on her face, neon reflections in the glass, natural skin texture with visible pores, 85mm lens, shallow depth of field. A small chalkboard behind her reads "Open Late · Fresh Pastries" in neat handwriting, and that is the only text on it.

Both wrote "Open Late · Fresh Pastries" correctly. Seedream 5.5 has the more candid, natural photo and the woman looks closer to 30, but it ignored "that is the only text on it" and added a line of made-up handwriting at the top of the board. GPT Image 2.6 kept the board clean and composed a more styled shot, with a latte and croissants in frame. She reads a bit older than 30.

This round: GPT Image 2.6, for following the text instruction.

Test 2: event poster with English and Japanese text

Text to image, 16:9, 2K:

A clean modern event poster for a fictional night market called "Lantern Street Market". Warm paper lanterns hang over a street of food stalls at blue hour. Large headline "LANTERN STREET MARKET" at the top, with the Japanese line "ちょうちん横丁ナイトマーケット" beneath it. Small info text at the bottom reads "Fri–Sun · 6 PM – Midnight · 120 Food Stalls · Free Entry". Crisp editorial layout, readable typography, rich warm light.

Both are usable posters with every requested line spelled right, Japanese included, and both filled the stall signs with real Japanese words. Seedream 5.5 went for a quieter, editorial look but added four bits of text we never asked for, such as "Good food brighter people" and "A brighter night together". GPT Image 2.6 printed only what was in the prompt and made the bottom info line larger and easier to read.

This round: GPT Image 2.6.

Test 3: sticker on a transparent background

Text to image, 1:1, 1K:

A cute die-cut sticker of a smiling cartoon avocado wearing tiny sunglasses and holding a surfboard, bold clean outlines, vibrant flat colors, with the words "Stay Chill" in rounded bubble letters under it.

On Seedream 5.5 we turned on Background: Transparent. GPT Image 2.6 has no such setting on our site, so we added "On a transparent background." to its prompt.

Both returned a PNG with a real alpha channel, so you can drop either sticker on any background without a remover. GPT Image 2.6 made the more polished sticker, with a clear avocado pit and bolder lettering; Seedream 5.5's avocado looks closer to a pear. Seedream did it for 4 credits instead of 10, and you do not have to remember the right words, because transparency is a switch.

This round: a draw. GPT Image 2.6 for the art, Seedream 5.5 for the price and the switch.

Test 4: edit a product photo

Image to image, one reference photo, 4:3, 2K. This is the photo both models got:

Keep the canister, its label text and the camera angle exactly the same. Change only the setting: place it on a dark walnut table in a cozy morning kitchen with soft steam rising from a cup of coffee beside it.

Both kept the label word for word, down to "Single Origin · Ethiopia". GPT Image 2.6 also kept the camera angle, the plant on the left and the scattered beans, so it reads as the same product shot in a new room. Seedream 5.5 pulled the camera back and up and dropped the beans.

This round: GPT Image 2.6.

Test 5: three edits in a row

We started from the same canister photo and fed each result back in as the next input, at 4:3 and 1K:

1. "Keep the canister, its label text and the camera angle exactly the same. Change only the setting: place it on a white marble kitchen counter in a bright minimalist kitchen."
2. "Keep everything in the scene exactly the same: the canister, its label, the coffee beans and the camera angle. Change only the lighting: warm golden-hour sunlight streaming in from the left window, with long soft shadows across the marble."
3. "Keep everything exactly the same: the canister, its label, the coffee beans, the camera angle and the golden-hour light. Add only two props on the counter: a white ceramic cup of latte with heart latte art to the right of the canister, and a small linen napkin under the cup."

Seedream 5.5, rounds 1–3 · 23 s, 21 s, 15 s · 6 credits each

GPT Image 2.6 Sunburst, rounds 1–3 · 41 s, 29 s, 41 s · 7, 9 and 7 credits

Multi-round editing is the feature ByteDance leads with for Seedream 5.5, and it did hold up: after three rounds the canister, label and beans are unchanged and the picture is still sharp. GPT Image 2.6 held up just as well and placed the latte cup exactly where we asked, to the right of the canister. Seedream put the cup in front of the jar, where it covers the end of the small label line.

Three rounds is a short run. We have not tested 10 or more rounds yet.

This round: GPT Image 2.6, narrowly.

What it costs

• Seedream 5.5: a fixed 4 credits at 1K or 7 at 2K, plus 2 per reference photo. A transparent PNG costs the same.
• GPT Image 2.6 Sunburst: holds up to 15 credits at 1K, 30 at 2K or 60 at 4K, plus 5 per reference photo, then refunds what the image did not use. Ours settled at 7 to 13. GPT Image 2.6 Economy is a fixed 5 credits at 1K if you want OpenAI's model for less.

Across our seven test images, Seedream 5.5 used 45 credits and GPT Image 2.6 Sunburst used 68. On a new account with 15 free credits, that is three Seedream 5.5 images at 1K, or one Sunburst image, since Sunburst needs the full 15-credit cap in your balance to start. Credits are only used when an image comes out.

Which one should you use?

• GPT Image 2.6 when the picture has to come out exactly as described: product edits that must keep the framing, posters where nothing extra may appear, and anything you need at 4K.
• Seedream 5.5 when you are making many images or still trying prompts: it was faster in every run and cheaper, and transparent PNGs are one switch. Its 2K images are also larger, 4.2 MP against 3.1 MP at 3:4.

A good workflow is to draft on Seedream 5.5 and run the final version on GPT Image 2.6.

Try both on ImagesArt

Both models have their own page with text to image and image to image. Seedream 5.5 adds the Transparent background setting and a Layers tab that splits one photo into separate PNG layers. GPT Image 2.6 offers Economy, Flare and Sunburst in one GPT Image 2.6 generator. No OpenAI or ByteDance account is needed.

Open the Seedream 5.5 generator →

Related reading

Comparing with Google's model instead? Read Seedream 5.5 vs Nano Banana Pro, where we ran the same five tests.

FAQ

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