GLM-5.3 Flash vs GPT-5.1 Thinking: Specs & Benchmark Comparison
| Characteristic | GLM-5.3 Flash | GPT-5.1 Thinking |
|---|---|---|
| Company | Zhipu AI | OpenAI |
| Release Date | August 26, 2026 | November 11, 2025 |
| Parameters | 320B | — |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 256K |
| Context (output) | 131K | 128K |
| Input Price / 1M | $0.15 | $3.00 |
| Output Price / 1M | $0.50 | $12.00 |
| Average Score | 0.6 | 0.9 |
Verdict
GLM-5.3 Flash leads in 3 out of 4 comparison categories.
Overall Performance
Both models show comparable average scores: GLM-5.3 Flash — 0.6, GPT-5.1 Thinking — 0.9.
API Cost
GLM-5.3 Flash is 23.1x cheaper: input $0.15/1M vs $3.00/1M tokens.
Context Window
GLM-5.3 Flash supports a larger context: 1M vs 256K tokens.
Recency
GLM-5.3 Flash is newer: released 8/26/2026 vs 11/11/2025.
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Frequently Asked Questions
Which is better for coding — GLM-5.3 Flash or GPT-5.1 Thinking?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — GLM-5.3 Flash or GPT-5.1 Thinking?
GLM-5.3 Flash is cheaper for input: $0.15 per 1M tokens vs $3.00.
Which has a larger context window — GLM-5.3 Flash or GPT-5.1 Thinking?
GLM-5.3 Flash supports a larger context: 1,048,576 tokens vs 256,000.
The GLM-5.3 Flash and GPT-5.1 Thinking 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 Flash or GPT-5.1 Thinking page. See also the complete list of AI model comparisons.