Who ranks #1 on the IOI leaderboard?
As of August 20, 2026, Claude Opus 5 by Anthropic ranks #1 on IOI at 91.7%. API pricing is $5.00/M input and $25.00/M output.
As of August 20, 2026, Claude Opus 5 is #1 for IOI at 91.7%. Ranked by the IOI score 45 models in this index have a published IOI score. IOI leaderboard with live API prices. IOI — International Olympiad in Informatics programming contest problems.
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As of August 20, 2026, Claude Opus 5 by Anthropic is #1 for IOI at 91.7%. Ranked by the IOI score This board also tracks IOI. Next on the same board: GPT-5.6 Sol and Qwen3.8 Max. This ioi leaderboard ranks models by IOI. Scores come from public evals. Prices are the live API rates in the table above.
Sources: OpenAI API pricing (https://developers.openai.com/api/docs/pricing); Anthropic Claude API pricing (https://platform.claude.com/docs/en/about-claude/pricing); Gemini API pricing (https://ai.google.dev/gemini-api/docs/pricing)
| Rank | Model | IOI | Input /M | Output /M |
|---|---|---|---|---|
| 1 | Claude Opus 5 | 91.7% | $5.00 | $25.00 |
| 2 | GPT-5.6 Sol | 86.7% | $5.00 | $30.00 |
| 3 | Qwen3.8 Max | 73% | $2.00 | $6.00 |
| 4 | GPT-5.6 Luna | 72.9% | $0.20 | $1.20 |
| 5 | Claude Fable 5 | 72.3% | $10.00 | $50.00 |
| 6 | GPT-5.4 | 67.8% | $2.50 | $15.00 |
| 7 | GPT-5.6 Terra | 65.3% | $2.00 | $12.00 |
| 8 | GPT-5.2 | 54.8% | $1.75 | $14.00 |
Rank one eval at a time. All LLM benchmarks.
As of August 20, 2026, Claude Opus 5 by Anthropic ranks #1 on IOI at 91.7%. API pricing is $5.00/M input and $25.00/M output.
The current IOI ranking as of August 20, 2026 is 1. Claude Opus 5 at 91.7%; 2. GPT-5.6 Sol at 86.7%; 3. Qwen3.8 Max at 73%.
Qwen3 235B A22B is the cheapest scored model on this ioi leaderboard at $0.10/M input and $0.10/M output ($0.20 blended). Claude Opus 5 still leads IOI at 91.7%.
Not automatically. Claude Opus 5 leads IOI, but a cheaper scored model can be the better production choice if the quality gap is small. Use the table to weigh IOI against input/output price, context window, and related evals.
Scores and API prices on this page are refreshed from published evals and provider rates. The snapshot is labeled August 20, 2026. Treat it as a current index, not a one-off blog post.
IOI — International Olympiad in Informatics programming contest problems. This page ranks models that have published a IOI score, with live API token prices on the same row.
This page is the IOI leaderboard. Models are sorted by IOI, with input and output token prices on the same row so you can weigh score against cost. Official boards often omit price; that comparison is the point of this index.
Official eval pages own the methodology. This page keeps the published IOI score next to live API $/M so you can pick a production SKU, not only a trophy number.