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Atria Dawn Preview vs GPT-5.3 Codex

Atria Dawn Preview leads the LLM Stats Score 52.3 to 36.5.

Shanghai AI Laboratory · OpenAI · Updated for 2026

Which is better?

Atria Dawn Preview leads the overall LLM Stats Score 52.3 to 36.5, ranking #10 overall.

In the 1 individual benchmarks reported for both models, Atria Dawn Preview wins 1; this is a narrower head-to-head signal than the composite indexes.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Atria Dawn Preview

  • overall performance matters — it scores 52.3 and ranks #10 on LLM Stats
  • your work emphasizes reasoning and agents — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results
  • you want the most recent training data — it shipped Sep 2026
  • you need open weights you can self-host or fine-tune

Choose GPT-5.3 Codex

  • you want predictable pricing at $1.75/M input and $14.00/M output

At a glance

The differences that matter most.

Atria Dawn Preview
Shanghai AI Laboratory
GPT-5.3 Codex
OpenAI
Core performance indexes
LLM Stats Score
52.3
#10
36.5
#75
Reasoning
50.5
#12
37.2
#70
Coding
36.2
#22
29.9
#53
Agents
38.8
#10
22.8
#57
Cost, coverage & limits
Benchmark wins
1 of 1
0 of 1
Input price
— / M
$1.75 / M
Output price
— / M
$14.00 / M
Context window
—
400,000

Individual benchmarks

12 reported for Atria Dawn Preview · 6 for GPT-5.3 Codex

1 shared

Atria Dawn Preview outperforms in 1 benchmarks (SWE-Bench Pro), while GPT-5.3 Codex is better at 0 benchmarks.

Atria Dawn Preview significantly outperforms across most benchmarks.

Thu Sep 17 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only GPT-5.3 Codex specifies input context (400,000 tokens). Only GPT-5.3 Codex specifies output context (128,000 tokens).

Shanghai AI Laboratory
Atria Dawn Preview
Input- tokens
Output- tokens
OpenAI
GPT-5.3 Codex
Input400,000 tokens
Output128,000 tokens
Thu Sep 17 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

GPT-5.3 Codex supports multimodal inputs, whereas Atria Dawn Preview does not.

GPT-5.3 Codex can handle both text and other forms of data like images, making it suitable for multimodal applications.

Atria Dawn Preview

Text
Images
Audio
Video

GPT-5.3 Codex

Text
Images
Audio
Video

License

Usage and distribution terms

Atria Dawn Preview is licensed under MIT, while GPT-5.3 Codex uses a proprietary license.

License differences may affect how you can use these models in commercial or open-source projects.

Atria Dawn Preview

MIT

Open weights

GPT-5.3 Codex

Proprietary

Closed source

Release Timeline

When each model was launched

Atria Dawn Preview was released on 2026-09-11, while GPT-5.3 Codex was released on 2026-02-05.

Atria Dawn Preview is 7 months newer than GPT-5.3 Codex.

Atria Dawn Preview

Sep 11, 2026

5 days ago

7mo newer
GPT-5.3 Codex

Feb 5, 2026

7 months ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Atria Dawn Preview and GPT-5.3 Codex side-by-side, then vote on the output you prefer.

Atria Dawn Preview
✓ Preferred
GPT-5.3 Codex
Open in Playground

FAQ

Common questions about Atria Dawn Preview vs GPT-5.3 Codex.

Which is better, Atria Dawn Preview or GPT-5.3 Codex?

Atria Dawn Preview leads the LLM Stats Score 52.3 to 36.5. Atria Dawn Preview is made by Shanghai AI Laboratory and GPT-5.3 Codex is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Atria Dawn Preview compare to GPT-5.3 Codex in benchmarks?

Atria Dawn Preview scores DeepSearchQA: 96.0%, BrowseComp: 92.5%, CyberGym: 86.5%, MLE-Bench Lite: 86.2%, WideSearch: 81.9%. GPT-5.3 Codex scores SWE-Lancer (IC-Diamond subset): 81.4%, Cybersecurity CTFs: 77.6%, Terminal-Bench 2.0: 77.3%, LiveBench: 72.8%, OSWorld-Verified: 64.7%.

What are the context window sizes for Atria Dawn Preview and GPT-5.3 Codex?

Atria Dawn Preview supports an unknown number of tokens and GPT-5.3 Codex supports 400K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Atria Dawn Preview and GPT-5.3 Codex?

Key differences include LLM Stats Score (52.3 vs 36.5), multimodal support (no vs yes), licensing (MIT vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes Atria Dawn Preview and GPT-5.3 Codex?

Atria Dawn Preview is developed by Shanghai AI Laboratory and GPT-5.3 Codex is developed by OpenAI.

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