text model comparison
Claude Opus 4.8 vs Claude Sonnet 5.5
Claude Opus 4.8 and Claude Sonnet 5.5 are both current text models, from Anthropic. Claude Sonnet 5.5 is 60% cheaper per 1M input tokens than Claude Opus 4.8, $2 vs $5. On Arena Text, Claude Opus 4.8 scores 1482 Elo and Claude Sonnet 5.5 1477 Elo (Arena, measured October 28, 2026). Both accept 1,000,000 tokens of context.
- Higher Arena Text
- Claude Opus 4.81482 Elo against 1477 Elo
- Lower price per 1M input tokens
- Claude Sonnet 5.5$2 against $5
- Newer release
- Claude Sonnet 5.5Sep 2026 against May 2026
Data verified November 3, 2026 · Dataset 2026-11-03
Side by side
Claude Opus 4.8 and Claude Sonnet 5.5, line by line
Prices in effect today, compared at the same tier wherever both list one. The better value in each row is highlighted.
| Fact | Claude Opus 4.8 | Claude Sonnet 5.5 |
|---|---|---|
| Price | ||
| Price per 1M input tokens | $5 | $2 (better) |
| Price per 1M output tokens | $25 | $10 (better) |
| Independent benchmarks | ||
| Arena Text | 1482 Elo (#13 of 51) (better) | 1477 Elo (#19 of 51) |
| Arena WebDev | 1556 Elo (#30 of 45) | 1770 Elo (#3 of 45) (better) |
| FrontierMath Tiers 1-3 (v2) | 80% (#16 of 42) | 88.8% (#8 of 42) (better) |
| GPQA Diamond | 91% (#22 of 41) | 95.6% (#3 of 41) (better) |
| SimpleQA Verified | 53% (#18 of 38) (better) | 46.5% (#23 of 38) |
| LiveBench Overall | 78.93 points (#2 of 4) | Not measured |
| Specs | ||
| Provider | Anthropic | Anthropic |
| Release date | May 28, 2026 | September 28, 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 · 2026-11-03Epoch AI · 2026-11-03LiveBench · 2026-06-25
Charts
Against every current text model
Where Claude Opus 4.8 and Claude Sonnet 5.5 land among the current models of their task, on every independent benchmark, on price and on context.
Where each stands
On Arena Text, Claude Opus 4.8 ranks #13 and Claude Sonnet 5.5 #19 of 51 current models. Each bar is the share of current models it beats: on score, price and context.
Independent benchmarks
Arena Text
Claude Opus 4.8:#13of 51
1,482 Elo · ahead of 72%
Claude Sonnet 5.5:#19of 51
1,477 Elo · ahead of 62%
Arena WebDev
Claude Opus 4.8:#30of 45
1,556 Elo · ahead of 34%
Claude Sonnet 5.5:#3of 45
1,770 Elo · ahead of 95%
FrontierMath Tiers 1-3 (v2)
Claude Opus 4.8:#16of 42
80% · ahead of 63%
Claude Sonnet 5.5:#8of 42
88.8% · ahead of 83%
GPQA Diamond
Claude Opus 4.8:#22of 41
91% · ahead of 48%
Claude Sonnet 5.5:#3of 41
95.6% · ahead of 95%
SimpleQA Verified
Claude Opus 4.8:#18of 38
53% · ahead of 54%
Claude Sonnet 5.5:#23of 38
46.5% · ahead of 41%
Price and context
Price per 1M input tokens
Claude Opus 4.8:#46of 52
$5 · cheaper than 8%
Claude Sonnet 5.5:#29of 52
$2 · cheaper than 24%
Price per 1M output tokens
Claude Opus 4.8:#46of 52
$25 · cheaper than 10%
Claude Sonnet 5.5:#34of 52
$10 · cheaper than 25%
Context window
Claude Opus 4.8:#26of 64
1M tokens · longer than 22%
Claude Sonnet 5.5:#26of 64
1M tokens · longer than 22%
Quality against price
Claude Opus 4.8 scores 1,482 at $10; Claude Sonnet 5.5 scores 1,477 at $4 (blended price per 1M tokens). The line joins the current models no other beats on both price and Arena Text score; hover any point to name it.
Quality against price: the data
| Model | Provider | Blended price per 1M tokens | Arena Text (Elo) |
|---|---|---|---|
| Gemini 4 Argon | $4 | 1,520 | |
| Claude Opus 5.5 | Anthropic | $8 | 1,509 |
| Muse Wonder | Meta | $8 | 1,507 |
| Claude Fable 5 | Anthropic | $20 | 1,504 |
| Claude Fable 5.1 | Anthropic | $20 | 1,504 |
| Gemini 3.8 Flash | $1.50 | 1,496 | |
| Muse Spark 1.3 | Meta | $2 | 1,495 |
| Claude Opus 5 | Anthropic | $10 | 1,492 |
| Kimi K3 | Moonshot Kimi | $6 | 1,488 |
| GPT-5.6 Sol | OpenAI | $8 | 1,485 |
| Gemini 3.6 Flash | $3 | 1,483 | |
| GPT-5.5 | OpenAI | $11 | 1,482 |
| Claude Opus 4.8 | Anthropic | $10 | 1,482 |
| Qwen3.8-Max | Alibaba Qwen | $3 | 1,482 |
| GPT-6.1 Sol | OpenAI | $4 | 1,481 |
| GLM-5.3 | Z.ai | $2.15 | 1,481 |
| MiMo-V2.6-Pro | Xiaomi MiMo | $0.54 | 1,480 |
| Claude Sonnet 5.5 | Anthropic | $4 | 1,477 |
| GLM-5.3-Flash | Z.ai | $0.24 | 1,477 |
| GPT-6 Astra | OpenAI | $20 | 1,476 |
| DeepSeek-V4.1-Flash | DeepSeek | $0.52 | 1,476 |
| GPT-5.4 | OpenAI | $5.63 | 1,475 |
| Gemini 3 Flash Preview | $1.13 | 1,473 | |
| Grok 4.20 | xAI | $1.56 | 1,472 |
| GPT-5.6 Terra | OpenAI | $4.50 | 1,467 |
| Grok 4.5 | xAI | $3 | 1,465 |
| DeepSeek-V4-Pro | DeepSeek | $1.98 | 1,465 |
| Claude Sonnet 5 | Anthropic | $4 | 1,462 |
| GPT-6 Sol | OpenAI | $4 | 1,458 |
| Gemini 3.5 Flash-Lite | $0.85 | 1,456 | |
| Grok 4.6 | xAI | $3 | 1,455 |
| GPT-5.6 Luna | OpenAI | $0.45 | 1,453 |
| MiMo-V2.6-Flash | Xiaomi MiMo | $0.18 | 1,448 |
| Step 5 Preview | StepFun | $1.43 | 1,448 |
| Grok 4.3 | xAI | $1.56 | 1,442 |
| GPT-6 Luna | OpenAI | $0.20 | 1,441 |
| Grok 4.7 | xAI | $3 | 1,441 |
| Mistral Large 4 | Mistral AI | $1.05 | 1,432 |
| Claude Haiku 5.5 | Anthropic | $0.20 | 1,425 |
| GPT-4.1 | OpenAI | $3.50 | 1,415 |
| Solar Pro 4 | Upstage | $0.52 | 1,388 |
| GPT-4.1 mini | OpenAI | $0.70 | 1,383 |
| GPT-4.1 nano | OpenAI | $0.18 | 1,322 |
Cost
What each costs
Example workloads at each provider's listed rates, then every other rate either one lists. The cheaper figure in each row is highlighted.
The same work, priced
For 10M input and 2M output tokens, Claude Opus 4.8 costs 2.5 times as much as Claude Sonnet 5.5, at each provider's listed rates.
10M input and 2M output tokens
Claude Opus 4.8 costs 2.5× as much
- Claude Opus 4.8
- $100
- Claude Sonnet 5.5
- $40
The same, with 9M of the input tokens cached
Claude Opus 4.8 costs 2.6× as much
- Claude Opus 4.8
- $59.50
- Claude Sonnet 5.5
- $22.90
| Workload or rate | Claude Opus 4.8 | Claude Sonnet 5.5 |
|---|---|---|
| Example workloads | ||
| 10M input and 2M output tokens | $100 | $40 (better) |
| The same, with 9M of the input tokens cached | $59.50 | $22.90 (better) |
| The same, through the batch API | Not listed | $20 |
| Other listed rates | ||
| 1M input tokens, cached | $0.50 | $0.10 (better) |
| 1M input tokens, 5-minute cache write | Not listed | $2.50 |
| 1M input tokens, 1-hour cache write | Not listed | $4 |
| 1M input tokens, batch | Not listed | $1 |
| 1M output tokens, batch | Not listed | $5 |
Your own bill will differ. These figures use list prices and example workloads. The AI Model Cost Audit reviews your real usage, shortlists models that score as well for each task for less, and estimates the savings.
Launch price $100, regular price $150
Verdict
When to choose each
Claude Opus 4.8
Where it leads
- Higher Arena Text score, 1482 Elo vs 1477 Elo
- Higher SimpleQA Verified score, 53% vs 46.5%
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 Sonnet 5.5
Where it leads
- Lower input and output prices, $2 and $10 vs $5 and $25 per 1M tokens
- Higher Arena WebDev score, 1770 Elo vs 1556 Elo
- Higher FrontierMath Tiers 1-3 (v2) score, 88.8% vs 80%
- Higher GPQA Diamond score, 95.6% vs 91%
- Accepts image input
- Cheaper cached input, $0.10 vs $0.50 per 1M tokens
- Batch pricing, $1 input and $5 output per 1M tokens
Best for
- Production workloads that need frontier-adjacent quality at a mid-tier rate
- Latency-sensitive agent steps inside a larger pipeline
Watch out for
- Same list price as Claude Sonnet 5, so the gain is capability and cache economics rather than a cheaper rate card
- Anthropic positions Opus 5.5 rather than this as the default, so reach for Sonnet 5.5 when latency matters more than peak capability
From benchmark to production
Building on Claude Opus 4.8 or Claude Sonnet 5.5?
Public scores rarely hold on your own data. We test both models on your real tasks, then build the agent or pipeline around the one that wins.
AI Model Cost AuditLaunch price $100, regular price $150What the audit includes
FAQ
Claude Opus 4.8 vs Claude Sonnet 5.5 FAQ
Which is cheaper, Claude Opus 4.8 or Claude Sonnet 5.5?
Claude Sonnet 5.5 is 60% cheaper per 1M input tokens than Claude Opus 4.8, $2 vs $5. For 10M input and 2M output tokens, Claude Opus 4.8 costs $100 and Claude Sonnet 5.5 $40 at standard rates.
Which is cheaper with prompt caching, Claude Opus 4.8 or Claude Sonnet 5.5?
Claude Opus 4.8 charges $0.50 per 1M cached input tokens, 90% below its standard input rate, and Claude Sonnet 5.5 $0.10, 95% below. With 9M of 10M input tokens cached and 2M output tokens, Claude Opus 4.8 costs $59.50 and Claude Sonnet 5.5 $22.90.
Which scores higher on independent benchmarks, Claude Opus 4.8 or Claude Sonnet 5.5?
Claude Opus 4.8 leads on Arena Text, 1482 Elo to 1477 Elo; Claude Sonnet 5.5 leads on Arena WebDev, 1770 Elo to 1556 Elo; Claude Sonnet 5.5 leads on FrontierMath Tiers 1-3 (v2), 88.8% to 80%. Scores are independent evaluations, not either vendor's launch figures.
Which has the larger context window, Claude Opus 4.8 or Claude Sonnet 5.5?
Both accept 1,000,000 tokens of context.
How do Claude Opus 4.8 and Claude Sonnet 5.5 differ in features?
Claude Opus 4.8 takes text input; Claude Sonnet 5.5 takes text and image.
Further reading
More on Claude Opus 4.8 and Claude Sonnet 5.5
Articles on Claude Opus 4.8 and Claude Sonnet 5.5
- Claude Sonnet 5.5 vs GPT-6 Luna: Cost, Speed and AccuracySeptember 29, 2026
- Claude Sonnet 5.5: Benchmarks, Price and When to Use OpusSeptember 29, 2026
Related comparisons
- Claude Opus 4.8 vs Gemini 3.5 Flash
- Claude Haiku 5.5 vs Claude Sonnet 5.5
- Claude Haiku 5.5 vs Claude Opus 4.8
- Claude Sonnet 5.5 vs Mistral Large 4
- Claude Opus 4.8 vs Claude Opus 5.5
- Claude Sonnet 5.5 vs Gemini 4 Argon
- Claude Opus 4.8 vs Gemini 3.8 Flash
- Claude Sonnet 5.5 vs GPT-6.1 Sol
- Claude Opus 4.8 vs Claude Opus 5
- Claude Opus 5.5 vs Claude Sonnet 5.5
- Claude Opus 4.8 vs Kimi K3
- Claude Opus 5 vs Claude Sonnet 5.5
Production evaluation
Choosing between Claude Opus 4.8 and Claude Sonnet 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