AI Rankings
Claude Sonnet 5.5 vs GPT-6 Astra: Scores, Price and Which to Choose
Data updated
Read the model pages for the full picture: Claude Sonnet 5.5 and GPT-6 Astra.
Side by side
- Claude Sonnet 5.5
- GPT-6 Astra
- Epoch Capabilities IndexToo close to call
Combined score over many tests. Bar shows where it sits between the lowest and highest score we track.
Claude Sonnet 5.5:166.2GPT-6 Astra:168.8 - Arena text ratingToo close to call
Rating from head-to-head votes by people. Bar shows where it sits between the lowest and highest score we track.
Claude Sonnet 5.5:1478GPT-6 Astra:1477 - Arena coding ratingToo close to call
Rating from head-to-head votes by people. Bar shows where it sits between the lowest and highest score we track.
Claude Sonnet 5.5:1528GPT-6 Astra:1543 - Arena web development ratingToo close to call
Rating from head-to-head votes by people. Bar shows where it sits between the lowest and highest score we track.
Claude Sonnet 5.5:1769GPT-6 Astra:1774 - Arena vision ratingToo close to call
Rating from head-to-head votes by people. Bar shows where it sits between the lowest and highest score we track.
Claude Sonnet 5.5:1265GPT-6 Astra:1285 - Humanity's Last ExamGPT-6 Astra leads
A large set of very hard, expert-written questions across many subjects, built to stay difficult for top AI models.
Claude Sonnet 5.5:46.1%GPT-6 Astra:Better: 54.8% - FrontierMath (Tiers 1-3)GPT-6 Astra leads
Original, very hard maths problems written by mathematicians.
Claude Sonnet 5.5:88.8%GPT-6 Astra:Better: 93.7% - GPQA DiamondToo close to call
Very hard multiple-choice science questions in biology, physics and chemistry, written by experts and designed so a quick web search does not give the answer.
Claude Sonnet 5.5:95.6%GPT-6 Astra:95.8% - OTIS Mock AIMEToo close to call
Maths competition problems in the style of the US AIME exam, from the 2024 and 2025 sets.
Claude Sonnet 5.5:100.0%GPT-6 Astra:100.0% - SimpleQA VerifiedGPT-6 Astra leads
Short factual questions that each have one correct answer.
Claude Sonnet 5.5:46.5%GPT-6 Astra:Better: 75.6% - Blended price per million tokensClaude Sonnet 5.5 costs less
Blended price: lower is better.
Claude Sonnet 5.5:Better: $4.00GPT-6 Astra:$20.00 - Context windowToo close to call
How much text it can read at once.
Claude Sonnet 5.5:1M tokensGPT-6 Astra:922K tokens
The numbers
| Measure | Claude Sonnet 5.5 | GPT-6 Astra |
|---|---|---|
| Epoch Capabilities IndexToo close to call | 166.2 | 168.8 |
| Arena text ratingToo close to call | 1478 | 1477 |
| Arena coding ratingToo close to call | 1528 | 1543 |
| Arena web development ratingToo close to call | 1769 | 1774 |
| Arena vision ratingToo close to call | 1265 | 1285 |
| Humanity's Last Exam | 46.1% | 54.8% |
| FrontierMath (Tiers 1-3) | 88.8% | 93.7% |
| GPQA DiamondToo close to call | 95.6% | 95.8% |
| OTIS Mock AIMEToo close to call | 100.0% | 100.0% |
| SimpleQA Verified | 46.5% | 75.6% |
| Blended price per million tokens | $4.00 | $20.00 |
| Context windowToo close to call | 1M tokens | 922K tokens |
What it costs in everyday terms
- 100 chats with Claude Sonnet 5.5
- $0.70
- Blended price $4.00 per million tokens.
- 100 chats with GPT-6 Astra
- $3.50
- Blended price $20.00 per million tokens.
Who should pick which
Pick Claude Sonnet 5.5 if these matter most
- Blended price per million tokens: $4.00 against $20.00
Pick GPT-6 Astra if these matter most
- Humanity's Last Exam: 54.8% against 46.1%
- FrontierMath (Tiers 1-3): 93.7% against 88.8%
- SimpleQA Verified: 75.6% against 46.5%
Too close to call: Epoch Capabilities Index, Arena text rating, Arena coding rating, Arena web development rating, Arena vision rating, GPQA Diamond, OTIS Mock AIME, Context window.
Scores come from tests and votes, not from your own work. Try both on a task you care about before you commit.
Questions about this comparison
- Which is better, Claude Sonnet 5.5 or GPT-6 Astra?
- GPT-6 Astra scores higher on 3 of 10 shared quality measures, Claude Sonnet 5.5 on 0. 7 measures are too close to call. Claude Sonnet 5.5 costs about 80% less than GPT-6 Astra on a blended price of $4.00 against $20.00 per million tokens. Which one is better for you depends on your task and budget, so test both on your own work.
- Which is cheaper, Claude Sonnet 5.5 or GPT-6 Astra?
- Claude Sonnet 5.5 is cheaper on blended price: $4.00 per million tokens for Claude Sonnet 5.5 against $20.00 for GPT-6 Astra. For 100 chats of about 1,000 tokens in and 500 tokens back, that is about $0.70 for Claude Sonnet 5.5 and $3.50 for GPT-6 Astra.
- Which is better for coding, Claude Sonnet 5.5 or GPT-6 Astra?
- On Arena coding rating they are too close to call (1528 and 1543).
Where this data comes from
- Epoch AI: Benchmark data: Epoch AI, 'Capabilities & benchmarking', epoch.ai/benchmarks (CC BY 4.0). We match models across sources, rank them and show them in charts. Scores are not changed. Epoch AI does not endorse this site.
- Arena (formerly LMArena): Human-preference ratings: Arena (arena.ai) leaderboard dataset, CC BY 4.0. We keep the latest published ratings, match them to models from other sources and rank them. Ratings are not changed. Arena does not endorse this site.
- LiteLLM model price list: Prices and context windows: LiteLLM model price list (github.com/BerriAI/litellm, MIT licence). We use the model maker's own price entry when there is one. Prices change often, so always confirm on the maker's site before you buy.
Newest data on this page: 26 Oct 2026. Prices are list prices and change often, so confirm on the maker's site before you buy. Sponsors never change a score or an order. How we calculate this · Report a mistake