Compare / head-to-head
GLM-5.1vsGPT-4o
GLM-5.1 leads 5 of 5 shared benchmarks. GLM-5.1 is 2.2x cheaper per token. GLM-5.1 has the larger context window (200K tokens).
Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.
Shared benchmarks
5 – 0
GLM-5.1 leads
Cheaper per token
GLM-5.1
2.2x cheaper, input + output
Larger context
GLM-5.1
200K tokens
Provider uptime (30d)
— · 94.2446%
Z.ai · OpenAI
GLM-5.1
Z.ai · released 2026-04-07
text
Quality
Benchmark matrix
5 shared · 2 only GLM-5.1 · 3 only GPT-4o| Benchmark | GLM-5.1 | GPT-4o | Δ | Edge |
|---|---|---|---|---|
| Reported by both · 5 | ||||
| GPQA Diamond | 89.9% ↗epoch | 46% ↗ | +43.9 pt | GLM-5.1 |
| FrontierMath Tiers 1-3 v2 (Epoch AI run) | 36.8% ↗epoch | 0.4% ↗epoch | +36.4 pt | GLM-5.1 |
| OTIS Mock AIME 2024-2025 (Epoch AI run) | 93.3% ↗epoch | 6.4% ↗epoch | +86.9 pt | GLM-5.1 |
| SimpleQA Verified | 34% ↗epoch | 26% ↗epoch | +8 pt | GLM-5.1 |
| SWE-bench Verified (Epoch AI run) | 74.2% ↗epoch | 31% ↗epoch | +43.2 pt | GLM-5.1 |
| Only GLM-5.1 reports · 2 | ||||
| AIME 2026 | 95.8% ↗matharena ⚠ | not reported | — | — |
| LMArena Elo | 1462.4 ↗ | not reported | — | — |
| Only GPT-4o reports · 3 | ||||
| MMLU | not reported | 85.7% ↗ | — | — |
| AIME 2025 | not reported | 11.7% ↗matharena | — | — |
| AIME 2024 | not reported | 13.1% ↗ | — | — |
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-5.1 minus GPT-4o 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-5.1 | GPT-4o | Edge |
|---|---|---|---|
| Context window | 200K tokens | 128K tokens | GLM-5.1 |
| Max output | 131K tokens | 16K tokens | GLM-5.1 |
| Input price / 1M | $1.4 ↗ | $2.5 ↗ | GLM-5.1 |
| Output price / 1M | $4.4 ↗ | $10 ↗ | GLM-5.1 |
| Cached input / 1M | $0.26 ↗ | $1.25 ↗ | GLM-5.1 |
| Input + output / 1M Lower is cheaper. List prices; batch, tool and regional fees excluded. | $5.8 | $12.5 | GLM-5.1 |
| Modalities | text | text · vision | GPT-4o |
| Released | 2026-04-07 | 2024-05-13 | — |
| Cited benchmark scores | 7 | 9 | — |
Reliability
Provider status
Last 60 days · refreshed daily on this page · live on /statusMore matchups
GLM-5.1 vs …
Models sharing the most benchmarksMore matchups
GPT-4o vs …
Models sharing the most benchmarksBuilt by Respan
Which one wins on your data?
Public benchmarks are a starting point. Run GLM-5.1 and GPT-4o on your own prompts with Respan evals, or route to either through one gateway key with automatic failover.