ResearchLLM Verifications Leaderboard

Data as of · 78 models, 80 questions · reviewed by Suhas Bhairav · methodology

Head to head · tested 27 Oct 2026

Claude Haiku 5.5 vs Claude Opus 5.5: accuracy, speed and price

Claude Opus 5.5 is more accurate; Claude Haiku 5.5 is cheaper.

AnthropicClaude Haiku 5.568.8% score · #26$0.00048 per question192 tok/sAnthropicClaude Opus 5.585.0% score · #1$0.015 per question129 tok/s

Verdict

Built from the measurements below

  • Claude Opus 5.5 is more accurate: 85.0% against 68.8% on the same 80 questions, a 16.2-point gap that is statistically significant.
  • Claude Haiku 5.5 is 31× cheaper per question as billed ($0.00048 vs $0.015), reasoning tokens included.
  • Claude Haiku 5.5 generates text 1.5× faster: 192 tokens per second against 129.
  • Claude Haiku 5.5 starts answering sooner: 0.7 s to the first token, against 2.3 s for Claude Opus 5.5.

Which should you choose?

Choose Claude Haiku 5.5 for the lower cost per correct answer ($0.0007 against $0.017), faster streaming and a quicker first token. Choose Claude Opus 5.5 for the most accurate answers of the two. The widest subject gap is in law: Claude Opus 5.5 answered 5 of 6 correctly, Claude Haiku 5.5 2 of 6. With so few questions per subject, treat this as a lead to test on your own prompts, not a result.

Accuracy gap -16.2 points (z = -2.44). A winner is called only when z is at least 1.96, the usual 95% threshold. Speed, latency and price need a 10% margin.

Head to head

Same questions, same prompt, same API

MeasureClaude Haiku 5.5Claude Opus 5.5Edge
Verification scoreHigher is better68.8%85.0%Claude Opus 5.5
Cost per questionLower is better$0.00048$0.015Claude Haiku 5.5
Output speedHigher is better192129Claude Haiku 5.5
Time to first tokenLower is better0.7 s2.3 sClaude Haiku 5.5
End-to-end response timeLower is better3.9 s7.6 sClaude Haiku 5.5
Tokens per questionLower is better873645Claude Opus 5.5
Context windowHigher is better1M1MSimilar

Side by side

Bars are scaled to the larger of the two values. The winner on each measure is marked in bold.

Every measure

Claude Haiku 5.5 first, Claude Opus 5.5 second

Verification scorehigher is better
Claude Haiku 5.568.8%
Claude Opus 5.585.0%
Cost per questionlower is better
Claude Haiku 5.5$0.00048
Claude Opus 5.5$0.015
Output speedhigher is better
Claude Haiku 5.5192
Claude Opus 5.5129
Time to first tokenlower is better
Claude Haiku 5.50.7 s
Claude Opus 5.52.3 s
End-to-end response timelower is better
Claude Haiku 5.53.9 s
Claude Opus 5.57.6 s
Tokens per questionlower is better
Claude Haiku 5.5873
Claude Opus 5.5645
Context windowhigher is better
Claude Haiku 5.51M
Claude Opus 5.51M

Score vs. cost per question

Both models in color, every other model in grey

Most attractive quadrant0255075100$0.00001$0.0001$0.001$0.01$0.10Cost per question (USD, log) →Verification score (%) →Qwen3.8 2.4T A95BCommand AReka Flash 3Gemma 4 26B A4BGemma 4 31BQwen3.5 397B A17BHermes 4 405BMuse WonderGrok 4.7o3gpt-oss-20bMinistral 3 3B 2512Nova Micro 1.0Phi 4Granite 4.2 8BHy3GLM 5.3 FlashSolar Pro 4Trinity Large ThinkingMiniMax M3Mistral Large 4Claude Opus 5.5GPT-6.1 SolGemini 4 ArgonGPT-5.4GPT-6 Lunagpt-oss-120bLlama 4 Maverick

Specifications and pricing

From OpenRouter's catalogue, plus the leaderboard's test dates

SpecificationClaude Haiku 5.5Claude Opus 5.5
CreatorAnthropicAnthropic
Released7 Oct 202622 Sept 2026
Weights——
ReasoningYesYes
Inputtext, image, filetext, image, file
Outputtexttext
Context window1M tokens1M tokens
Knowledge cutoff——
List price in / out per 1M$0.1 / $0.5$4 / $20
Blended price per 1M (3:1)$0.20$8.00
Cheapest hostGoogle · $0.1 / $0.5Amazon Bedrock · $4 / $20
Hosts on OpenRouter55
Last tested25 Oct 202625 Oct 2026

Compare any two models →

Claude Haiku 5.5 vs Claude Opus 5.5: frequently asked questions

Is Claude Haiku 5.5 better than Claude Opus 5.5?
Claude Opus 5.5 is more accurate: it answered 68 of 80 questions correctly (85.0%) against 55 of 80 (68.8%) for Claude Haiku 5.5. Claude Opus 5.5 is more accurate; Claude Haiku 5.5 is cheaper.
Which is cheaper, Claude Haiku 5.5 or Claude Opus 5.5?
Claude Haiku 5.5 is cheaper: $0.00048 per question as billed, against $0.015. List prices: Claude Haiku 5.5 $0.1 in / $0.5 out, Claude Opus 5.5 $4 in / $20 out per million tokens.
Which is faster, Claude Haiku 5.5 or Claude Opus 5.5?
Claude Haiku 5.5 is faster at 192 output tokens per second, against 129. Time to first token: 0.7 s for Claude Haiku 5.5, 2.3 s for Claude Opus 5.5.
Which has the larger context window, Claude Haiku 5.5 or Claude Opus 5.5?
Both accept about the same amount of context: 1M and 1M tokens.