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Qwen-Image-2.1 vs Closed Models: 4 Tests on RTX 4090

We tested Qwen-Image-2.1 locally on RTX 4090 against Ideogram 4.5 and FLUX 3. Fast and cheap, but closed models win on text, layout, and edits.

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Qwen-Image-2.1 vs Closed Models: 4 Tests on RTX 4090

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Qwen-Image-2.1 is currently the top open image model in the Artificial Analysis ranking, so we put it through the same four tests we ran for Ideogram 4.5 and FLUX 3. It ran locally on our RTX 4090, while competitors used API access. The results are mixed. A single image looks great and generates in 6-20 seconds for pennies in electricity. But for text rendering, adhering to specified layouts, and consecutive edits, closed models are clearly superior.

Related reading: Qwen-Image-2.1 Fashion Photography: Twelve Styles Tested.

The Artificial Analysis ranking is based on votes from people choosing the better-looking of two images. It’s a good measure of aesthetics, but it doesn’t tell you whether a model will correctly render complex text, place a mug in the corner of the frame, or survive the tenth edit. That’s why we measure these separately, using the same scripts and prompts we used for the competition.

Qwen-Image-2.1 Hub - everything about the model: tests, installation, license.

How We Tested Qwen-Image-2.1

  • Hardware: RTX 4090 (24 GB), ComfyUI, Qwen-Image-2.1 int8 variant (16.6 GB files), 25 steps, euler sampler, cfg 1.0 - settings from the official template.
  • Competitors: same tasks via fal.ai API, described in Ideogram 4.5 and FLUX 3 tests from October 1, 2026.
  • Single attempt per task, fixed seed, no cherry-picking results.
  • Date: October 2, 2026.

Results Summary

Test Qwen-Image-2.1 (local) Best result in field
Text rendering (13 strings to reproduce, tested in Polish) 6/13 13/13 - GPT Image 2.5, Nano Banana Pro, Nano Banana 2, Grok
Objects in specified positions (16) 2/16, IoU 0.17 16/16, IoU 0.89 - FLUX 3 with JSON boxes
Detail in large frame 2752 × 1536, effectively 3.1 Mpx 16.8 Mpx - FLUX 3 in 4K
Readable small signs (8) 2/8 8/8 - GPT Image 2.5, Grok, Seedream
10 consecutive edits (SSIM after 10th step) 0.11 0.95 - Ideogram 4.5
Time per 1024 × 1024 image ~6 s competitors via API: 20-60 s
Cost per image electricity, fraction of a cent $0.024-0.22 via API

Test 1: Text Rendering

Four tasks: a sale poster, a milk bar menu, a book cover, and a pierogi box. A total of 13 text strings to reproduce letter-for-letter. We ran this test in Polish, a heavily inflected language with diacritical marks, making it a useful proxy for non-English text rendering. We verified automatic OCR on each image manually. In the menu, we corrected one false error (the text was actually correct).

Text strings without errors, out of 13
GPT Image 2.5 Sunburst13
Nano Banana Pro13
Grok Imagine 213
Ideogram 4.511
FLUX.2 Max10
Qwen Image 3 (API)8
Qwen-Image-2.1 (local)6
Milk bar menu generated in Qwen-Image-2.1, with text error
Menu: 5 out of 6 correct, one spelling error
Book cover in Qwen-Image-2.1 with errors in diacritical marks
Book cover: errors in diacritical marks

Large, clear words with diacritics came out well. The problem starts with more difficult character combinations and small print. On the pierogi box, text was misspelled, and on the poster as well. This model isn’t suitable for graphics with complex diacritical text without manual correction.

Test 2: Objects in Specified Positions

Four scenes with four objects each, each with precisely described position in percentages of frame width and height. Qwen-Image-2.1 doesn’t have a bounding box format, so it received the same text description as Nano Banana Pro, GPT Image 2.5, and Seedream. A vision model marked where objects landed, and we calculated overlap with the specified box (IoU).

Model Average IoU Objects in position
FLUX 3 Image (JSON boxes) 0.89 16/16
Seedream 5.0 Pro 0.79 15/16
GPT Image 2.5 Sunburst 0.54 11/16
Nano Banana Pro 0.48 7/16
Ideogram 4.5 0.37 7/16
Qwen Image 3 (API) 0.35 6/16
Qwen-Image-2.1 (local) 0.17 2/16
Kitchen with clock, kettle, apples and cat in Qwen-Image-2.1
Kitchen: all objects present, but none in their specified box
Mineral water ad in Qwen-Image-2.1, objects arranged in a row
Water ad: bottle, lemon, mint and ice arranged in a row

The images are beautiful and have everything we asked for. The model simply arranges the scene its own way, treating the described percentages as a loose suggestion. If your project requires space for a logo or text, FLUX 3 with boxes or Seedream is a better choice.

Test 3: Detail in Large Frame

The same frame of a market square with six signs, a kiosk, and a tram. Qwen-Image-2.1 generated it in the largest supported 16:9 format, 2752 × 1536 px, in 49 seconds. Effectively that’s about 3.1 Mpx of true detail, roughly the same as Grok Imagine 2 (3.3 Mpx). Only 2 out of 8 text strings are readable. The signs became so small they merged into blobs.

Market square at dusk generated locally in Qwen-Image-2.1
Qwen-Image-2.1, 2752 × 1536 px, 49 s on RTX 4090
1:1 crop from Qwen-Image-2.1 image
Qwen-Image-2.11:1 crop, 330 px
1:1 crop from FLUX 3 Image in 4K
FLUX 3 Image1:1 crop, 654 px

Test 4: 10 Consecutive Edits

A photo of a bakery and 10 edits in sequence: door, sticker, scooter instead of bike, no car, new sign, lavender, coat, cat, price, no trash can. Each subsequent edit starts from the result of the previous one. We measured how much remained of fragments that shouldn’t have changed (SSIM, 1 = no change).

SSIM of unchanged fragments after 10 edits
Ideogram 4.50.95
Seedream 5.0 Pro0.58
Nano Banana 20.57
Nano Banana Pro0.54
Qwen Image 3 (API)0.48
GPT Image 2.5 Sunburst0.43
FLUX.2 Max0.32
Grok Imagine 20.22
Qwen-Image-2.1 (local, int8)0.11
Bakery after 2 edits in Qwen-Image-2.1, clean image
After 2nd edit: clean, instructions executed
Bakery after 10 edits in Qwen-Image-2.1 with strong color noise
After 10th edit: color noise across entire image

Qwen-Image-2.1 executes the instructions themselves well: the door turned green, the bike became a scooter, the car disappeared, and a sign appeared. However, each subsequent pass adds grain and oversaturates colors. After the third edit, artifacts are visible, and after the sixth, the image is only fit for the trash. A single edit looks good, which aligns with the model’s high 18th place in the Artificial Analysis editing ranking. However, that ranking evaluates one step, not ten.

Fair disclaimer: we tested the int8 variant in ComfyUI. On our first attempt, we set the reference image resolution to 1024 with 2048 output, and noise grew even faster (SSIM 0.08). After equalizing both resolutions, it improved, but the problem didn’t disappear. It’s possible that the full bf16 version or different sampler settings would give a cleaner result. We didn’t verify this because bf16 doesn’t fit in 24 GB together with the text encoder.

Practical advice: when making several edits in a row, always edit the original with all changes added in one prompt, instead of editing edits.

What This Means

  • For fast, beautiful images without text Qwen-Image-2.1 is excellent: 6 seconds per 1K image, zero API fees, and high scores in blind voting.
  • For graphics with text choose GPT Image 2.5 or Nano Banana Pro.
  • For projects with precise layout choose FLUX 3 with JSON boxes.
  • For series of edits on one photo choose Ideogram 4.5 or FLUX 3.
  • Remember the license. Qwen Research only permits research and evaluation. Commercial use requires a separate agreement with Alibaba - details in the text about the license.

The complete comparison of open models is in our open image models ranking, and we cover Qwen-Image-2.1’s place in the Artificial Analysis ranking in a separate news item.

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Frequently Asked Questions

Is Qwen-Image-2.1 better than Nano Banana Pro?

Not in Artificial Analysis blind voting: Nano Banana Pro has 1101 points, while Qwen-Image-2.1 has 1034. In our tests, Nano Banana Pro clearly won in text rendering (13 to 6) and maintaining layout. Qwen wins on price and the fact that it works offline.

How long does one image take on RTX 4090?

In our measurements, about 6 seconds at 1024 × 1024, 10 seconds at 1536 × 1024, 44 seconds at 2048 × 2048, and 49 seconds at 2752 × 1536. Editing at 1536 × 1024 took about 20 seconds. The first run after loading the model is several times slower.

Why do consecutive edits degrade the image?

Each edit encodes and decodes the entire image from scratch, and small distortions accumulate. Ideogram 4.5 and FLUX 3 have modes that restore unchanged pixels from the original. Qwen-Image-2.1 in ComfyUI doesn’t have such a mode.

Can I use Qwen-Image-2.1 commercially?

Not without a separate license. Qwen Research only permits research and evaluation of the model.

Kinetyra

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Piotr Olszewski

Editor and publisher · Quantslant

I edit and publish Quantslant. AI tools help with research, drafts and translation; choosing topics, running the tests, checking facts and the decision to publish are mine, and so is the responsibility for what appears here.

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