GLM-5.3 vs GPT-5.1 High: Specs & Benchmark Comparison
GLM-5.3 is developed by Zhipu AI, while GPT-5.1 High comes from OpenAI. GPT-5.1 High was released in November 2025, and GLM-5.3 followed 9 months later in August 2026. GLM-5.3 has a published size of about 753 billion parameters; OpenAI has not disclosed the parameter count of GPT-5.1 High.
We have 17 benchmark results for GLM-5.3 and 2 benchmark results for GPT-5.1 High, but they were measured on different benchmarks, so there is no like-for-like scoreboard.
GLM-5.3 is the cheaper API at $1.40 per million input tokens and $4.40 per million output tokens, about 43% below GPT-5.1 High at $2 and $8. GLM-5.3 takes the larger context window at 1M tokens, compared with 256K for GPT-5.1 High. GLM-5.3 accepts text as input, while GPT-5.1 High accepts text and images.
| Characteristic | GLM-5.3 | GPT-5.1 High |
|---|---|---|
| Company | Zhipu AI | OpenAI |
| Release Date | August 14, 2026 | November 11, 2025 |
| Parameters | 753B | — |
| Multimodal | No | Yes |
| Context (input) | 1.0M | 256K |
| Context (output) | 131K | 128K |
| Input Price / 1M | $1.40 | $2.00 |
| Output Price / 1M | $4.40 | $8.00 |
| Average Score | 52.2% | 94.0% |
Verdict
GLM-5.3 leads in 3 out of 4 comparison categories.
Both models show comparable average scores: GLM-5.3 — 0.5, GPT-5.1 High — 0.9.
GLM-5.3 is 1.7x cheaper: input $1.40/1M vs $2.00/1M tokens.
GLM-5.3 supports a larger context: 1M vs 256K tokens.
GLM-5.3 is newer: released 8/14/2026 vs 11/11/2025.
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Frequently Asked Questions
Which is better for coding — GLM-5.3 or GPT-5.1 High?
Which model is cheaper — GLM-5.3 or GPT-5.1 High?
Which has a larger context window — GLM-5.3 or GPT-5.1 High?
The GLM-5.3 and GPT-5.1 High comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the GLM-5.3 or GPT-5.1 High page. See also the complete list of AI model comparisons.