text model comparison
Claude Opus 4.8 vs Claude Opus 5.5
Claude Opus 4.8 and Claude Opus 5.5 are both current text models, from Anthropic. Claude Opus 5.5 is 20% cheaper per 1M input tokens than Claude Opus 4.8, $4 vs $5. On Arena Text, Claude Opus 4.8 scores 1481 Elo and Claude Opus 5.5 1507 Elo (Arena, measured October 8, 2026). Both accept 1,000,000 tokens of context.
Data verified October 12, 2026 · Dataset 2026-10-12
Side by side
Standard-tier prices in effect today. The better value in each row is highlighted.
| Fact | Claude Opus 4.8 | Claude Opus 5.5 |
|---|---|---|
| Price per 1M input tokens | $5 | $4 (better) |
| Price per 1M output tokens | $25 | $20 (better) |
| Cost of 10M input and 2M output tokens | $100 | $80 (better) |
| Arena Text | 1481 Elo (#15 of 39) | 1507 Elo (#1 of 39) (better) |
| GPQA Diamond | 91% (#20 of 37) (better) | 90.6% (#22 of 37) |
| FrontierMath Tiers 1-3 (v2) | 80% (#13 of 37) | 91.2% (#3 of 37) (better) |
| SimpleQA Verified | 53% (#17 of 34) | 72.2% (#4 of 34) (better) |
| LiveBench Overall | 78.93 points (#2 of 5) | Not measured |
| Provider | Anthropic | Anthropic |
| Release date | May 28, 2026 | September 22, 2026 |
| Access | API only | API only |
| Context window | 1,000,000 tokens | 1,000,000 tokens |
| Max output | Not reported | 128,000 tokens |
| Input | text | text, image |
| Output | text | text |
Scores:Arena · 2026-10-12Epoch AI · 2026-10-12LiveBench · 2026-06-25
When to choose each
Claude Opus 4.8
Best for
- Long-running agentic and professional-work evaluations
Watch out for
- Maximum output length is not represented because the approved source set does not establish one unambiguously
Claude Opus 5.5
Best for
- Long-running agentic coding and knowledge work as the general-purpose default
- Cache-heavy agent loops where the 0.05x read multiplier compounds
Watch out for
- The API effort default is medium here, not high as on Claude Fable 5.1 and Claude Sonnet 5.5, so a like-for-like comparison has to set effort explicitly
- The 4.7-generation tokenizer produces roughly 30% more tokens for the same text than Claude Sonnet 4.6 and earlier, so per-token rates do not compare directly across generations
Claude Opus 4.8 vs Claude Opus 5.5 FAQ
Which is cheaper, Claude Opus 4.8 or Claude Opus 5.5?
Claude Opus 5.5 is 20% cheaper per 1M input tokens than Claude Opus 4.8, $4 vs $5. For 10M input and 2M output tokens, Claude Opus 4.8 costs $100 and Claude Opus 5.5 $80 at standard rates.
Which scores higher on independent benchmarks, Claude Opus 4.8 or Claude Opus 5.5?
Claude Opus 5.5 leads on Arena Text, 1507 Elo to 1481 Elo; Claude Opus 4.8 leads on GPQA Diamond, 91% to 90.6%; Claude Opus 5.5 leads on FrontierMath Tiers 1-3 (v2), 91.2% to 80%. Scores are independent evaluations, not either vendor's launch figures.
Which has the larger context window, Claude Opus 4.8 or Claude Opus 5.5?
Both accept 1,000,000 tokens of context.
Related comparisons
- Claude Fable 5.1 vs Claude Opus 5.5
- Claude Fable 5 vs Claude Opus 5.5
- Claude Opus 4.8 vs Claude Opus 5
- Claude Opus 4.8 vs Gemini 3.5 Flash
- Claude Opus 4.8 vs Gemini 3.8 Flash
- Claude Opus 4.8 vs GPT-5.5
- Claude Opus 4.8 vs GPT-5.6 Sol
- Claude Opus 4.8 vs Kimi K3
- Claude Opus 5.5 vs Gemini 3.8 Flash
- Claude Opus 5.5 vs GPT-5.5
Production evaluation
Choosing between Claude Opus 4.8 and Claude Opus 5.5?
Public benchmarks narrow the shortlist. We run both on your own tasks, data and cost limits, then build the routing and review controls to run the winner in production.
- A head-to-head evaluation on your real workload
- Routing between models by cost and difficulty