Compare / head-to-head
GLM-4.5-AirvsGPT-5.1
GPT-5.1 leads 2 of 2 shared benchmarks. GLM-4.5-Air is 8.7x cheaper per token. GPT-5.1 has the larger context window (400K tokens).
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
0 – 2
GPT-5.1 leads
Cheaper per token
GLM-4.5-Air
8.7x cheaper, input + output
Larger context
GPT-5.1
400K tokens
Provider uptime (30d)
— · 94.2446%
Z.ai · OpenAI
GLM-4.5-Air
Z.ai
text
Quality
Benchmark matrix
2 shared · 0 only GLM-4.5-Air · 4 only GPT-5.1| Benchmark | GLM-4.5-Air | GPT-5.1 | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 2 | ||||
| AIME 2025 | 83.3% ↗matharena ⚠ | 94.2% ↗matharena ⚠ | -10.9 pt | GPT-5.1 |
| LMArena Elo | 1383.6 ↗ | 1422.6 ↗ | -39 | GPT-5.1 |
| Only GLM-4.5-Air reports · 0 | ||||
| GLM-4.5-Air reports nothing GPT-5.1 does not. | ||||
| Only GPT-5.1 reports · 4 | ||||
| GPQA Diamond | not reported | 87.6% ↗epoch | — | — |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | not reported | 88.6% ↗epoch | — | — |
| SimpleQA Verified | not reported | 48% ↗epoch | — | — |
| SWE-bench Verified (Epoch AI run) | not reported | 68% ↗epoch | — | — |
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is GLM-4.5-Air minus GPT-5.1 in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing
Side by side
Official pricing pages and model cards| Spec | GLM-4.5-Air | GPT-5.1 | Edge |
|---|---|---|---|
| Context window | 128K tokens | 400K tokens | GPT-5.1 |
| Max output | 98K tokens | 128K tokens | GPT-5.1 |
| Input price / 1M | $0.2 ↗ | $1.25 ↗ | GLM-4.5-Air |
| Output price / 1M | $1.1 ↗ | $10 ↗ | GLM-4.5-Air |
| Cached input / 1M | $0.03 ↗ | $0.125 ↗ | GLM-4.5-Air |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $1.3 | $11.25 | GLM-4.5-Air |
| Modalities | text | text · vision | GPT-5.1 |
| Released | — | 2025-11-13 | — |
| Cited benchmark scores | 2 | 6 | — |
Reliability
Provider status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
GLM-4.5-Air vs …
Models sharing the most benchmarksMore matchups
GPT-5.1 vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run GLM-4.5-Air and GPT-5.1 on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.