Claude Opus 4.8 vs GPT-5.4: flagship reasoning or workhorse value?
Anthropic's premium reasoning flagship against OpenAI's cost-effective workhorse.
Claude Opus 4.8 is Anthropic's latest flagship, built for deep reasoning, complex planning, and nuanced analysis. GPT-5.4 is OpenAI's workhorse model, balancing cost and capability for everyday production workloads. Opus 4.8 costs roughly 2x more per token. The question is whether your task genuinely needs Opus-level reasoning depth.
Cost Comparison
Based on 100,000 input tokens (50% cached), 5,000 output tokens, and 100 requests.
Side-by-side specs
| Spec | Claude Opus 4.8 | GPT-5.4 |
|---|---|---|
| Input Cost (per M) | $5.00 | $2.50 (better on this spec) |
| Output Cost (per M) | $25.00 | $15.00 (better on this spec) |
| Cached Input (per M) | $0.50 | $0.25 (better on this spec) |
| Batch Discount | 50% | 50% |
How they differ
Claude Opus 4.8: $5/M input, $25/M output, 90% caching discount ($0.50/M cached), 50% batch discount. GPT-5.4: $2.50/M input, $15/M output, 90% caching discount ($0.25/M cached), 50% batch discount. For a typical 100K input + 10K output request, Opus 4.8 costs $0.75, GPT-5.4 costs $0.40. Over a million requests, that's $750K vs $400K — a $350K difference. Opus 4.8 leads on graduate-level reasoning, mathematical proofs, and multi-step agentic tasks. GPT-5.4 is competitive or better on general knowledge, coding, and instruction following at half the price.
Verdict
GPT-5.4 for most production workloads: it's cheaper and more than capable enough for RAG, chat, coding, and content generation. Claude Opus 4.8 for tasks where reasoning depth directly impacts business outcomes: legal analysis, scientific research, complex financial modeling, and multi-step autonomous agents where a wrong answer costs more than the API savings.
Which should you pick?
Choose Claude Opus 4.8
Tasks where reasoning depth directly impacts business outcomes: legal analysis, scientific research, complex financial modeling, and multi-step autonomous agents. The premium is justified when a wrong answer costs more than the API savings.
Choose GPT-5.4
Most production workloads: RAG, chat, coding, and content generation. GPT-5.4 is more than capable enough for these tasks at half the price.