# OpenAI GPT-OSS 120B vs Claude Opus 4.8

On provider list prices, OpenAI GPT-OSS 120B costs $0.15 per million input tokens against $5 for Claude Opus 4.8: 33.3x apart. Output is $0.60 against $25 (41.7x). On Allocate both bill at list plus the 7% transaction fee.

## Specifications

| | OpenAI GPT-OSS 120B | Claude Opus 4.8 |
| --- | --- | --- |
| Lab | OpenAI | Anthropic |
| Access | Open weights | API only |
| Context window | 128K tokens | 200K tokens |
| List price, input | $0.15 / M tokens | $5 / M tokens |
| List price, output | $0.60 / M tokens | $25 / M tokens |
| Cached input | n/a | n/a |
| License | Custom license | Proprietary API |
| Fine-tunable | Yes | No |

Specifications and provider list prices from the Allocate catalog, checked 2026-07-08. Billed price is list plus the 7% transaction fee.

## What the numbers say

Take 1,000,000 requests a month at 1,200 input and 350 output tokens each. That workload costs $390 a month on OpenAI GPT-OSS 120B and $14,750 on Claude Opus 4.8 at list: a gap of $14,360, or 37.8x.

Claude Opus 4.8 reads 200K tokens per request against 128K for OpenAI GPT-OSS 120B, 1.5x the window. That decides which one can take whole documents without splitting them.

## Choose OpenAI GPT-OSS 120B for

- The lower list price ($0.15 in / $0.60 out per M tokens)
- Open weights you can fine-tune and own

## Choose Claude Opus 4.8 for

- Hardest reasoning problems
- High-stakes analysis
- Escalation tier for agents

## Common questions

### Which is cheaper, OpenAI GPT-OSS 120B or Claude Opus 4.8?

OpenAI GPT-OSS 120B, on this workload shape. At list prices it is $0.15/$0.60 per million tokens in and out against $5/$25 for Claude Opus 4.8. Billed on Allocate: $0.16/$0.64 against $5.35/$26.75, list plus 7%.

### Which has the bigger context window?

Claude Opus 4.8: 200,000 tokens (200K) against 131,072 (128K) for OpenAI GPT-OSS 120B.

### Can I fine-tune OpenAI GPT-OSS 120B or Claude Opus 4.8?

OpenAI GPT-OSS 120B publishes open weights (Custom license) and can be fine-tuned on your own data. Claude Opus 4.8 is a closed model served over API; its weights are not available.

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[HTML page](https://allocate.network/compare/openai-gpt-oss-120b-vs-opus-4-8) · [OpenAI GPT-OSS 120B](https://allocate.network/models/openai-gpt-oss-120b.md) · [Claude Opus 4.8](https://allocate.network/models/opus-4-8.md) · [Machine-readable catalog](https://allocate.network/catalog.json)