Question 1

What does this Claude Opus 4.8 vs GPT-5 Chat (latest) comparison cover?

Accepted Answer

It brings together documented inputs and outputs, token limits, deployment terms and available pricing. When both models have source-linked, verified results on a shared benchmark, those results are shown with their individual sources. The comparison is a starting point for evaluating your own workload.

Question 2

Which is cheaper: Claude Opus 4.8 or GPT-5 Chat (latest)?

Accepted Answer

Claude Opus 4.8 lists $5.00 input and $25.00 output per 1M tokens. GPT-5 Chat (latest) lists $1.25 input and $10.00 output. The cheaper workload depends on the mix of input and output. Long-context tiers, caching, batch processing and retries can change the bill.

Question 3

Which has the larger context window: Claude Opus 4.8 or GPT-5 Chat (latest)?

Accepted Answer

Claude Opus 4.8 lists 1M tokens and GPT-5 Chat (latest) lists 400K. Claude Opus 4.8 therefore has the larger recorded context window, but capacity alone is not a quality score.

Question 4

Which is faster: Claude Opus 4.8 or GPT-5 Chat (latest)?

Accepted Answer

There is no matched speed measurement for both models with the same source, host, region and date. Test the same prompts at your expected concurrency and measure time to the first useful response as well as complete task time.

Question 5

What input and output types do Claude Opus 4.8 and GPT-5 Chat (latest) support?

Accepted Answer

Claude Opus 4.8 records text, image, pdf input and text output. GPT-5 Chat (latest) records text, image input and text output. “Not documented” means the current source record is incomplete; it does not prove that a modality is unsupported.

Question 6

Should I choose Claude Opus 4.8 or GPT-5 Chat (latest)?

Accepted Answer

Consider Claude Opus 4.8 if you need larger context. Consider GPT-5 Chat (latest) if you need a lower listed input rate or a lower listed output rate. Test both on the same representative examples and judge the output against your acceptance criteria. Include tool failures, retries and the time to a completed task.

Specification	Claude Opus 4.8	GPT-5 Chat (latest)
Provider	Anthropic	OpenAI
Listed pricing route	Anthropic	OpenAI
Model family	claude-opus	gpt-codex
Accepted inputs	text, image, pdf	text, image
Produced outputs	text	text
Context window	1MHigher	400K
Max output	128K	128K
Input price / 1M	$5.00	$1.25Lower
Output price / 1M	$25.00	$10.00Lower
Reasoning mode	Documented	Documented
Tool calling	Documented	Not documented
Image input	Documented	Documented
Audio input	Not documented	Not documented
Structured output	Not documented	Documented
License	Proprietary	Proprietary

Claude Opus 4.8 vs GPT-5 Chat (latest)

Claude Opus 4.8

GPT-5 Chat (latest)

Key differences

Pricing, limits and capabilities

Which model should you choose?

Documentation and model profiles

Questions people ask

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