Compare AI models side by side
Pick 2 for a head to head, or up to 4 for a ranked summary. Official API prices and LMArena scores, checked 2026-10-18.
GPT-6.1 Sol costs less; Claude Opus 5.5 wins more LMArena tasks.
GPT-6.1 Sol is 2x cheaper on input and output. Claude Opus 5.5 scores 82 points higher for creative writing; GPT-6.1 Sol scores 3 points higher for vision. Across 7 shared LMArena tasks, Claude Opus 5.5 leads 6 to 1. A medium month (20M input + 5M output tokens) costs $90 on GPT-6.1 Sol and $180 on Claude Opus 5.5.
- Pick GPT-6.1 Sol if you want the lower bill ($90 vs $180 for a medium month), you care most about vision (+3) or you reuse long prompts (cached input $0.10 vs $0.20).
- Pick Claude Opus 5.5 if you care most about creative writing (+82), chat (+42) and roleplay (+19).
Medium: 20M input + 5M output tokens a month at list price (short-context rate, no caching or batch discounts).
Marked side is better: lower for prices, higher for context and scores. Bars are scaled to the larger of the two.
| Spec | GPT-6.1 Sol | Claude Opus 5.5 |
|---|---|---|
| Price per 1M tokens | ||
| Input | $2 | $4 |
| Cached input | $0.10 | $0.20 |
| Output | $10 | $20 |
| Blend 3:1 | $4 | $8 |
| Sample month, medium | $90 | $180 |
| Context | ||
| Context window | 1.05M tokens | 1M tokens |
| Quality (LMArena, out of 100) | ||
| Coding | 82/100 #4 of 23 | 100/100 #1 of 23 |
| Chat | 30/100 #10 of 25 | 72/100 #3 of 25 |
| Creative writing | 18/100 #12 of 25 | 100/100 #1 of 25 |
| Roleplay and characters | 15/100 #11 of 25 | 34/100 #4 of 25 |
| Reasoning and math | 39/100 #12 of 24 | 53/100 #6 of 24 |
| Vision | 85/100 #2 of 21 | 82/100 #3 of 21 |
| Long documents | Not ranked | Not ranked |
| Cheap bulk and agents | 84/100 #4 of 23 | 100/100 #1 of 23 |
| Details | ||
| Provider | OpenAI | Anthropic |
| API model id | gpt-6.1-sol | claude-opus-5.5 |
| Notes | Prompts up to 272K. Longer prompts cost $4 in, $15 out. | 5-minute cache writes $5. |
| Sources | ||
| Last checked | 2026-10-18 | 2026-10-18 |
| Official pricing | OpenAI pricing | Anthropic pricing |
Plans from data checked hourly against each vendor's official pricing page. Vendors state limits in different units, so we quote them as published. Team and enterprise plans are per seat.
API prices in USD per 1M tokens from each provider's official pricing page. Blend 3:1 = (3 x input + output) / 4. Sample month = stated input and output tokens at the list price, no caching. Quality: relative score out of 100 on each LMArena leaderboard (100 = top model we price on that board, n/a = not ranked there), data licensed CC BY 4.0. See how we pick.
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FAQ
How do I compare two AI models?
Pick a provider and model in each column. With two models you get a head-to-head verdict, mirrored bars for price, context and each LMArena task, and a pick-this-if line. The default is GPT-6.1 Sol vs Claude Opus 5.5.
Can I compare 3 or 4 models?
Yes. Use + Add model. With 3 or 4 you get a summary strip (best value, cheapest, highest quality, longest context), inline bars in every row and the best model per LMArena task.
What does the sample month assume?
Light is 2M input + 0.5M output tokens, medium 20M input + 5M output tokens, heavy 200M input + 50M output tokens a month, at each provider's list price with no caching or batch discounts.
Where do the scores come from?
From the LMArena leaderboard dataset (CC BY 4.0), shown as a relative score out of 100 per task. Models that are not ranked show n/a.