# Z-Image
Z-Image is a 6-billion-parameter open-weight text-to-image foundation model developed by Tongyi MAI, Alibaba's Tongyi research unit, released as Z-Image-Turbo on November 26, 2025 and as the undistilled base model on January 27, 2026 under the Apache 2.0 license.[1](https://github.com/Tongyi-MAI/Z-Image) • [2](https://howaiworks.ai/models/z-image) Alibaba positions it as a photorealistic generator that matches models an order of magnitude larger while running on consumer graphics cards with less than 16 GB of VRAM.[3](https://tongyi-mai.github.io/Z-Image-blog/) This article covers the model release itself; the broader Tongyi family and Alibaba's Qwen-Image model are separate subjects.
| Fact | Detail |
|---|---|
| Developer | Tongyi MAI (Alibaba) |
| First release | Z-Image-Turbo, November 26, 2025[1](https://github.com/Tongyi-MAI/Z-Image) |
| Base model | Z-Image, January 27, 2026[1](https://github.com/Tongyi-MAI/Z-Image) |
| Parameters | ~6.15B in the diffusion transformer (DiT only)[2](https://howaiworks.ai/models/z-image) |
| License | Apache 2.0, no revenue, field-of-use, or geographic restrictions[2](https://howaiworks.ai/models/z-image) |
| Turbo sampling | 8 steps, no classifier-free guidance, fine-tunable including with LoRA via a training adapter[2](https://howaiworks.ai/models/z-image) • [8](https://github.com/bghira/SimpleTuner/blob/main/documentation/quickstart/ZIMAGE.md) |
| Vendor training cost | 314K H800 GPU hours, ~$628K (vendor-reported, unverified)[4](https://arxiv.org/html/2511.22699v5) |
| Adoption | 933,580 downloads in a trailing 30-day window; 6.66M all-time (2026)[2](https://howaiworks.ai/models/z-image) |
## What Z-Image is
The family comprises four announced variants: Z-Image-Turbo (a distilled fast generator), Z-Image (the base model), Z-Image-Omni-Base, and Z-Image-Edit, all under Apache 2.0. Turbo and the base model shipped on [Hugging Face](https://www.edgepedia.org/hugging-face) and [ModelScope](https://www.edgepedia.org/modelscope); Omni-Base and Edit remained listed as "To be released" as of the repository's last update.[1](https://github.com/Tongyi-MAI/Z-Image) The Hugging Face repos were created on November 25, 2025 and January 23, 2026 respectively, and the technical report appeared on arXiv on December 1, 2025.[1](https://github.com/Tongyi-MAI/Z-Image) • [2](https://howaiworks.ai/models/z-image) One independent review gives the Turbo release as November 27, 2025 with 500K+ first-day downloads; the project's own news log says November 26.[5](https://theaibench.ai/models/z-image-turbo/)
## Architecture and training as published
All architecture and training figures below are vendor-reported from the technical report unless noted. Z-Image uses a Single-Stream Multi-Modal Diffusion Transformer (S3-DiT) in which text tokens, visual semantic tokens, and VAE image tokens are concatenated at the sequence level, trained with a flow matching objective. It uses Qwen3-4B as the text encoder, chosen for its bilingual Chinese-English proficiency, the Flux VAE for image tokenization, and SigLIP 2 only for editing tasks.[4](https://arxiv.org/html/2511.22699v5)
Z-Image-Turbo is a 6-billion-parameter distilled model running at 8 function evaluations (NFEs) via Decoupled DMD distillation followed by DMDR reinforcement learning.[4](https://arxiv.org/html/2511.22699v5) Independent inspection of the checkpoints clarifies what "6B" counts: the base transformer shards total 12.31 GB in bf16, consistent with about 6.15 billion parameters, and the [Qwen3](https://www.edgepedia.org/qwen3) text encoder (hidden size 2560, 36 layers) is separate and not included in the figure.[2](https://howaiworks.ai/models/z-image) Turbo samples in 8 steps with guidance_scale 0.0 and no negative prompting, but can be fine-tuned, including with LoRA, using a training adapter; the base model uses 28 to 50 steps with guidance 3.0 to 5.0 and is fine-tunable.[8](https://github.com/bghira/SimpleTuner/blob/main/documentation/quickstart/ZIMAGE.md) Recommended resolutions run from 512×512 to 2048×2048.[2](https://howaiworks.ai/models/z-image)
The vendor reports that the complete training pipeline required 314K H800 GPU hours, about $628K at roughly $2 per GPU hour, split into 147.5K hours of low-resolution pre-training ($295K), 142.5K hours of omni-pre-training ($285K), and 24K hours of post-training ($48K).[4](https://arxiv.org/html/2511.22699v5) The training data itself (sources, scale, licensing) was not disclosed, and no source describes it.
## Benchmark results: vendor versus independent
**Vendor-reported results.** Alibaba's technical report cites an [Artificial Analysis](https://www.edgepedia.org/artificial-analysis) leaderboard placement from December 2025 in which Z-Image-Turbo achieved an Elo of 1,161, ranking 8th overall and first among open-source models, with the smallest parameter count and lowest inference cost ($5.00 per 1,000 images) among the top ten.[4](https://arxiv.org/html/2511.22699v5) On the Alibaba AI Arena, the company reports a 4th-place rank with Elo 1025 and a 45% win rate, behind Imagen 4 Ultra Preview (1048), gemini-2.5-flash-image-preview (1046), and [Seedream 4.0](https://www.edgepedia.org/seedream-4-0) (1039), and ahead of [Qwen-Image](https://www.edgepedia.org/qwen-image) (1008) and GPT Image 1 (986).[4](https://arxiv.org/html/2511.22699v5) • [6](https://zimage.net/Z_Image_Report.pdf) On text rendering benchmarks, the vendor reports LongText-Bench scores of 0.935 (English) and 0.936 (Chinese) for the base model, an OneIG English-track score of 0.546 ahead of Qwen-Image (0.539) and GPT Image 1 [High] (0.533) with English Text 0.987 and Chinese Text 0.988, and the highest average Word Accuracy on CVTG-2K at 0.8671 versus GPT-Image-1 (0.8569) and Qwen-Image (0.8288).[4](https://arxiv.org/html/2511.22699v5)
**Independent results.** Two independent checks cut against the vendor framing. First, Alibaba AI Arena, the source of the "state-of-the-art among open-source models" claim, is operated by Alibaba itself and cannot be independently verified from its published HTML.[2](https://howaiworks.ai/models/z-image) Second, the December 2025 leaderboard standing did not hold: as of July 8, 2026, Artificial Analysis places Z-Image Turbo at #69 overall with an Elo of 1,104, with NVIDIA's Cosmos3-Super-Text2Image as the open-weights leader at #8. On arena.ai (the former LMArena) it sits at #48 of 72 with an Elo of 1080.92, below Alibaba's own Apache-2.0 qwen-image-2512 at #33; the two Elo scales are not comparable.[2](https://howaiworks.ai/models/z-image)
## How it compares with Flux, Seedream and Qwen-Image
On parameter count, Z-Image's roughly 6.15B DiT is half of FLUX.1's 12B and far below Qwen-Image's 20B.[2](https://howaiworks.ai/models/z-image) • [7](https://lilting.ch/en/articles/z-image-vs-flux-sd) On licensing, Z-Image's Apache 2.0 carries no revenue cap, field-of-use, or geographic restriction, whereas FLUX.1's Dev weights are noncommercial.[2](https://howaiworks.ai/models/z-image) • [7](https://lilting.ch/en/articles/z-image-vs-flux-sd) On hardware, FLUX needs 24 GB or more for the full model and around 12 GB even quantized, while Z-Image runs quantized in about 6 GB, generating an image in roughly 30 seconds on RTX 2060-class GPUs.[7](https://lilting.ch/en/articles/z-image-vs-flux-sd)
The trade-offs are scope and ecosystem. Z-Image-Turbo is tuned for single-image text-to-image at around 1024², not compositional multi-reference editing like FLUX.2 dev.[5](https://theaibench.ai/models/z-image-turbo/) Turbo also cannot be fine-tuned, guided, or negatively prompted, and Alibaba's own table lists its diversity as "Low" and fine-tunability as N/A.[2](https://howaiworks.ai/models/z-image) Third-party tooling, community models, and tutorials were still sparse as of January 2026 compared with the [Stable Diffusion](https://www.edgepedia.org/stable-diffusion) and Flux ecosystems.[7](https://lilting.ch/en/articles/z-image-vs-flux-sd) No source provides a direct quality, speed, or cost comparison with [Midjourney](https://www.edgepedia.org/midjourney) or [GPT Image](https://www.edgepedia.org/gpt-image) beyond Alibaba's own arena and benchmark tables.
## Licensing, availability, hardware and cost
Both Hugging Face repos and the GitHub LICENSE file carry Apache 2.0 with no restrictions on commercial use. The weights are open; the training data is not released, so the model is open-weight rather than open-data.[2](https://howaiworks.ai/models/z-image)
**Hardware and speed.** The sub-second latency is a vendor claim for H800-class hardware, and the under-16 GB VRAM requirement is a vendor claim for consumer hardware.[1](https://github.com/Tongyi-MAI/Z-Image) • [3](https://tongyi-mai.github.io/Z-Image-blog/) [Community](https://www.edgepedia.org/community) measurements are more granular: about 6 GB quantized (int4) or roughly 12 GB native, fitting hardware as inexpensive as an Intel Arc B580 12 GB ($249).[5](https://theaibench.ai/models/z-image-turbo/) • [7](https://lilting.ch/en/articles/z-image-vs-flux-sd) stable-diffusion.cpp supports inference on as little as 4 GB of VRAM across CUDA and Vulkan, and Cache-DiT delivers nearly 4× speedup on 4 GPUs.[1](https://github.com/Tongyi-MAI/Z-Image) On consumer hardware, roughly 30 seconds per image on RTX 2060-class GPUs is the reported figure.[7](https://lilting.ch/en/articles/z-image-vs-flux-sd)
**Cost.** Alibaba publishes no first-party hosted API. Third-party [Replicate](https://www.edgepedia.org/replicate) pricing for Z-Image-Turbo is $0.0025 per image up to 0.5 MP, $0.005 up to 1 MP, and $0.01 up to 2 MP.[2](https://howaiworks.ai/models/z-image)
## Reception, adoption and criticisms
Adoption was substantial. Z-Image-Turbo recorded 933,580 Hugging Face downloads in a trailing 30-day window and 6,660,069 all-time, with 4,944 likes, making it the third most-downloaded text-to-image model on the Hub and the most-downloaded of Chinese origin as of the 2026 retrieval date.[2](https://howaiworks.ai/models/z-image) An independent benchmark site called it "the community daily driver for Apache-2.0 image gen in 2026."[5](https://theaibench.ai/models/z-image-turbo/)
The criticisms found in the sources concern methodology and follow-through rather than safety. The December 2025 "#1 open-source" leaderboard claim was stale by July 2026, when the same leaderboard ranked the model #69.[2](https://howaiworks.ai/models/z-image) The "state-of-the-art among open-source" claim rests on an Alibaba-operated arena.[2](https://howaiworks.ai/models/z-image) Two of the four advertised variants, Omni-Base and Edit, had never shipped, and the repository had been untouched since February 9, 2026.[2](https://howaiworks.ai/models/z-image) No source covers safety incidents, data-provenance disputes, lawsuits, or regulatory actions following the release.
## Recent developments
Z-Image sits in a 2025–2026 wave in which small, permissively licensed open-weight models from Chinese labs rival much larger closed systems. A 6B Apache 2.0 model competing with 20B+ and closed systems, at $5 per 1,000 images in its vendor-cited December 2025 ranking, marks a shift toward efficiency as the competitive axis in open image generation.[4](https://arxiv.org/html/2511.22699v5) • [2](https://howaiworks.ai/models/z-image) Community claims that the base model "knocked FLUX off the throne" circulated at release, though the arena supporting that claim was vendor-operated.[7](https://lilting.ch/en/articles/z-image-vs-flux-sd)
## References
1. Tongyi-MAI/Z-Image (GitHub repository) — https://github.com/Tongyi-MAI/Z-Image
2. Z-Image – AI Model | HowAIWorks.ai — https://howaiworks.ai/models/z-image
3. Z-Image official project homepage (Tongyi MAI, Alibaba Group) — https://tongyi-mai.github.io/Z-Image-blog/
4. Z-Image: An Efficient Image Generation Foundation Model with Single-Stream Diffusion Transformer — https://arxiv.org/html/2511.22699v5
5. Z-Image-Turbo | theaibench.ai — https://theaibench.ai/models/z-image-turbo/
6. Z-Image Report (PDF) — https://zimage.net/Z_Image_Report.pdf
7. Z-Image — Alibaba's image generator that reportedly surpasses FLUX (lilting channel) — https://lilting.ch/en/articles/z-image-vs-flux-sd
8. SimpleTuner/documentation/quickstart/ZIMAGE.md at main · bghira/SimpleTuner, https://github.com/bghira/SimpleTuner/blob/main/documentation/quickstart/ZIMAGE.md
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*Topic: Encyclopedia › Technology and the built world › Computing and digital systems › Modern AI: foundation models, generative AI, and the AI industry › Model families and named models › Image generation models*
*Initially written Sep 17, 2026 · Edited: Oct 11, 2026; Oct 15, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license