Claude Opus 4.8 vs gpt-oss-120b
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
Anthropic · May 2026
Anthropic's flagship Opus with adaptive thinking, effort controls and a 1M context — 88.6% on SWE-bench Verified at $5/$25.
OpenAI · Aug 2025
OpenAI's open-weights MoE reasoning model under Apache 2.0 — near o4-mini quality, runnable on a single 80GB GPU.
The verdict
Claude Opus 4.8 wins 1 of the 1 benchmarks these models share, against 0 for gpt-oss-120b. On price the gap is dramatic: gpt-oss-120b works out roughly 50x cheaper per blended million tokens. Claude Opus 4.8 also takes 1M of context versus 131K for gpt-oss-120b. And gpt-oss-120b is open-weights (Apache 2.0), so it can be self-hosted — a structural advantage if data control or vendor independence matters.
Benchmark head-to-head 1–0
Specs & pricing
| Claude Opus 4.8 | gpt-oss-120b | |
|---|---|---|
| modhub Index | — | — |
| Input price / 1M | $5 | $0.1 |
| Output price / 1M | $25 | $0.5 |
| Context window | 1M | 131K |
| Max output | 64K | 131K |
| Open weights | no | yes (Apache 2.0) |
| Reasoning model | yes | yes |
| Multimodal input | text, image | text |
| Knowledge cutoff | Mar 2026 | Jun 2024 |
| Released | May 2026 | Aug 2025 |
| Example monthly cost* | $87.50 | $1.75 |
* 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, Claude Opus 4.8 or gpt-oss-120b?
- Claude Opus 4.8 wins 1 of the 1 benchmarks these models share, against 0 for gpt-oss-120b. On price the gap is dramatic: gpt-oss-120b works out roughly 50x cheaper per blended million tokens. Claude Opus 4.8 also takes 1M of context versus 131K for gpt-oss-120b. And gpt-oss-120b is open-weights (Apache 2.0), so it can be self-hosted — a structural advantage if data control or vendor independence matters.
- Which is cheaper, Claude Opus 4.8 or gpt-oss-120b?
- Claude Opus 4.8 costs $5/$25 per million input/output tokens, while gpt-oss-120b costs $0.1/$0.5. For a typical workload of 10M input and 1.5M output tokens per month, that's $87.50 versus $1.75.
- Which model is better for coding, Claude Opus 4.8 or gpt-oss-120b?
- We don't yet track SWE-bench Verified results for both models; check their individual pages for coding-related scores.