Standard Compute
Model comparison 2026

Claude Opus 4.8 vs Claude Sonnet 5.5

Claude Opus 4.8
Anthropic · Frontier · Proprietary
$11/1M · 1M ctx
Claude Sonnet 5.5
Anthropic · Balanced · Proprietary
$4.40/1M · 1M ctx

Community vote

Pick a winner in each dimension. You can change your vote any time.

Output Quality
Correctness and depth of what it produces
Agentic Ability
Tool calls, instruction-following, and multi-step tasks
Speed
Tokens per second and time-to-first-token
Value for money
How much capability you get per dollar
Reliability
Consistent results: fewer refusals, loops and format breaks

Specs and pricing side by side

Spec
Opus 4.8
Sonnet 5.5
Maker
Anthropic
Anthropic
Blended price / 1M
$11
$4.40
Input / output
$5.00 in · $25 out / 1M tokens
$2.00 in · $10 out / 1M tokens
Context window
1M
1M
Open weights
No
No
Tool use
Yes
Yes
Reasoning
Yes
Yes
Output Quality
9.4
9.8
Agentic Ability
9.2
9.8
Speed
7.2
8.4
Value for money
7.5
8.8
Reliability
9.5
9.4

Pricing and capabilities synced from the OpenRouter catalogue. Scores are editorial (0–10).

Verdict: Opus 4.8 or Sonnet 5.5?

Updated 2026-10-13

Choose Claude Opus 4.8 if you want hard, high-stakes coding and reasoning where quality matters more than cost. Choose Claude Sonnet 5.5 if you want the everyday default for coding agents, escalating to Opus 5.5 only for the hardest tasks.

In our editorial scoring, Claude Sonnet 5.5 leads in 4 of five dimensions (output quality, agentic ability, speed and value for money), while Claude Opus 4.8 leads in 1. On price, Claude Opus 4.8 runs about $11 per 1M tokens (blended) and is proprietary; Claude Sonnet 5.5 is about $4.40 and proprietary.

Where Opus 4.8 falls short
  • Among the most expensive models per token
  • Superseded by Claude Opus 5.5, which costs less ($4/$20 vs $5/$25) and scores far higher
Full Opus 4.8 breakdown →
Where Sonnet 5.5 falls short
  • Artificial Analysis flags it as very verbose, which adds output tokens
  • Released September 2026, so its long-run track record is still short
Full Sonnet 5.5 breakdown →

The agent matters as much as the model. Compare AI agents →

Current Claude, GPT, Gemini and open models are included with Standard Compute

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Current frontier models Claude Opus 5.5 · Claude Sonnet 5.5

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