Claude Opus 4.8 vs Claude Sonnet 5

Claude Opus 4.8 and Claude Sonnet 5 are both current anthropic production-tier models. Claude Sonnet 5 is meaningfully cheaper at $3 / $15 per 1M. Claude Opus 4.8 leads on reasoning.

Specs side by side

Metric
Anthropic
Claude Opus 4.8
Anthropic
Claude Sonnet 5
Input price (per 1M)$5$3
Output price (per 1M)$25$15
Context window1M tokens1M tokens
Speed tierslowbalanced
Open weightsNoNo
EU regionYesYes
Free tierNoNo
Prompt cachingYesYes
Vision inputYesYes
Extended thinkingYesYes

When to choose each

Anthropic

Choose Claude Opus 4.8 if…

  • Reasoning is central to your workload
Anthropic

Choose Claude Sonnet 5 if…

  • Claude Sonnet 5 is in the same tier as Claude Opus 4.8 — pick by provider preference or API ecosystem

Benchmark delta

Claude Opus 4.8 leads on

  • Reasoning

Claude Sonnet 5 leads on

Claude Sonnet 5 has no meaningful benchmark lead in this pair.

FAQ — Claude Opus 4.8 vs Claude Sonnet 5

Claude Opus 4.8 vs Claude Sonnet 5 — which is better?

Claude Opus 4.8 and Claude Sonnet 5 are both current anthropic production-tier models. Claude Sonnet 5 is meaningfully cheaper at $3 / $15 per 1M. Claude Opus 4.8 leads on reasoning. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.

How does Claude Opus 4.8 pricing compare to Claude Sonnet 5?

Claude Opus 4.8 costs $5 / $25 per 1M vs Claude Sonnet 5 at $3 / $15 per 1M. Claude Sonnet 5 is cheaper on output tokens by roughly 67%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.

Does Claude Opus 4.8 or Claude Sonnet 5 have the bigger context window?

Claude Sonnet 5 has a 1M-token context window — 1× the 1M context of Claude Opus 4.8. Enough for entire codebases, books, or multi-document RAG.

Is there a free tier for Claude Opus 4.8 or Claude Sonnet 5?

Claude Opus 4.8: no — Free via Claude.ai web chat; API requires paid credits. Claude Sonnet 5: no — Default model on Claude.ai Free/Pro web chat; API requires paid credits.

Which is better for coding — Claude Opus 4.8 or Claude Sonnet 5?

Claude Opus 4.8 leads on coding benchmarks (Claude Opus 4.8: 97/100, Claude Sonnet 5: 95/100). For production coding agents also weigh tool-use performance — Claude Opus 4.8 scores 96, Claude Sonnet 5 scores 96.