GLM-5.1 vs OpenAI o3
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
Z.ai (Zhipu) · Apr 2026
The April 2026 GLM refresh — the first open-weights model to take #1 on SWE-bench Pro, edging out Claude Opus 4.6.
OpenAI · Apr 2025
OpenAI's dedicated 2025 reasoning model that pioneered thinking-with-images and agentic tool use within chain-of-thought.
The verdict
These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. GLM-5.1 is about 1.6x cheaper per blended million tokens (3:1 input:output mix). And GLM-5.1 is open-weights (MIT), so it can be self-hosted — a structural advantage if data control or vendor independence matters.
Specs & pricing
| GLM-5.1 | OpenAI o3 | |
|---|---|---|
| modhub Index | — | 68.9 |
| Input price / 1M | $1.4 | $2 |
| Output price / 1M | $4.4 | $8 |
| Context window | 200K | 200K |
| Max output | 128K | 100K |
| Open weights | yes (MIT) | no |
| Reasoning model | yes | yes |
| Multimodal input | text | text, image |
| Knowledge cutoff | Feb 2026 | May 2024 |
| Released | Apr 2026 | Apr 2025 |
| Example monthly cost* | $20.60 | $32.00 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, GLM-5.1 or OpenAI o3?
- These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. GLM-5.1 is about 1.6x cheaper per blended million tokens (3:1 input:output mix). And GLM-5.1 is open-weights (MIT), so it can be self-hosted — a structural advantage if data control or vendor independence matters.
- Which is cheaper, GLM-5.1 or OpenAI o3?
- GLM-5.1 costs $1.4/$4.4 per million input/output tokens, while OpenAI o3 costs $2/$8. For a typical workload of 10M input and 1.5M output tokens per month, that's $20.60 versus $32.00.
- Which model is better for coding, GLM-5.1 or OpenAI o3?
- We don't yet track SWE-bench Verified results for both models; check their individual pages for coding-related scores.