Z.ai open-sources GLM-5.3-Flash model
Z.ai released the code for GLM-5.3-Flash, a large language model it says is 10 times more cost-efficient than its predecessor. The model first appeared last week under the codename Ox Alpha on OpenRouter.
First seen 25 Aug, 06:42 UTC on Hugging Face · zai-org9 sourcesLast update 53d ago
Z.aiLaunch · 25 Aug
GLM 5.3 Flash
Open-weight model
$0.15 / $0.50per M tokens, in / out
1.31Mcontext
Openweights
How GLM 5.3 Flash compares
List prices per million tokens, context and Arena's text leaderboard, against Z.ai's other top models and the leading labs' best. The percentages are GLM 5.3 Flash's price against each.
| Model | Released | Input | Output | Context | Arena |
|---|---|---|---|---|---|
| GLM 5.3 Flash | August 2026 | $0.15 | $0.50 | 1.25M | #33 1475 |
| GLM 5.3 Prime | September 2026 | $2.80 -95% | $8.80 -94% | 1M | not ranked yet |
| GLM 5.3 FlashX | September 2026 | $0.37 -59% | $1.25 -60% | 1M | not ranked yet |
| Claude Opus 5.5 | September 2026 | $4.00 -96% | $20.00 -97% | 1M | #2 1507 |
| GPT-6 Astra | September 2026 | $10.00 -98% | $50.00 -99% | 1.05M | #30 1475 |
| Gemini 4 Argon | October 2026 | $2.00 -92% | $10.00 -95% | 1M | #1 1525 |
Arena ranks the best effort setting of each model among all models on its text leaderboard. Every model and price.
What the sources say
Linked, never rewritten. Official means the lab itself.
Official4
Hugging Face · zai-org· 25 Aug, 06:42zai-org/GLM-5.3 published on Hugging FaceHugging Face · zai-org· 25 Aug, 06:43zai-org/GLM-5.3-Flash published on Hugging FaceHugging Face · zai-org· 25 Aug, 06:43zai-org/GLM-5.3-BF16 published on Hugging FaceHugging Face · zai-org· 25 Aug, 06:45zai-org/GLM-5.3-Flash-BF16 published on Hugging FaceHow it unfolded
Every source in the order it appeared. Times in UTC.
25 Aug 06:42Hugging Face · zai-org zai-org/GLM-5.3 published on Hugging Face25 Aug 06:43Hugging Face · zai-org zai-org/GLM-5.3-Flash published on Hugging Face25 Aug 06:43Hugging Face · zai-org zai-org/GLM-5.3-BF16 published on Hugging Face25 Aug 06:45Hugging Face · zai-org zai-org/GLM-5.3-Flash-BF16 published on Hugging Face26 Aug 13:59OpenRouter Z.ai: GLM 5.3 Flash listed on OpenRouter26 Aug 14:58Hacker News GLM-5.3-Flash Intelligence, Performance and Price Analysis27 Aug 00:26SiliconANGLE Z.ai open-sources 'Ox Alpha' model as GLM-5.3-Flash27 Aug 10:24The Decoder GLM-5.3-Flash matches top models at a fraction of the cost, and runs without Nvidia28 Aug 15:20Hacker News GLM-5.3 is now open-weight
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