GPT-4o vs Claude Opus 5
A familiar workhorse against the most capable model on the list.
Side by side
| Attribute | GPT-4o | Claude Opus 5 |
|---|---|---|
| Input, per 1M tokens | $2.50 | $5.00 |
| Output, per 1M tokens | $10.00 | $25.00 |
| Context window | 128,000 | 1,000,000 |
| Provider | OpenAI | Anthropic |
| Tokenizer | o200k_base | Anthropic tokenizer |
| Long-context tier | none | none |
| Retires | no date announced | no date announced |
Which to choose
- On cost, GPT-4o is 2x cheaper per million input tokens. On a workload that reads far more than it writes, that ratio is close to the whole difference in the bill.
- On capacity, Claude Opus 5 holds more in one request. That matters only if you are near the smaller ceiling — below it, the extra room changes nothing.
What this page does not tell you. Which model produces better answers. That depends on your task, and this site has no benchmark data — everything above is drawn from published pricing and specifications. Compare quality by running your own prompts through both.
Common questions
- Is GPT-4o or Claude Opus 5 cheaper?
- GPT-4o is cheaper on input — $2.50 per million against $5.00, a difference of 2x. Output rates differ separately, and a workload heavy on generated text can reverse which one costs less overall.
- Which has the larger context window?
- Claude Opus 5, at 1,000,000 tokens against 128,000.
- Can I compare them on my own prompt?
- Yes. The calculator counts any text against every model at once, so you can see both figures for your actual workload rather than for a generic example.