Claude Haiku 4.5 vs Composer 2

Side-by-side benchmark comparison across agentic, coding, multimodal, knowledge, reasoning, and math workflows.

Claude Haiku 4.5 and Composer 2 finish on the same overall score, so this is less about a single winner and more about where the edge shows up. The headline says tie; the benchmark table is where the real choice happens.

Claude Haiku 4.5 is also the more expensive model on tokens at $0.80 input / $4.00 output per 1M tokens, versus $0.50 input / $2.50 output per 1M tokens for Composer 2. Composer 2 is the reasoning model in the pair, while Claude Haiku 4.5 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use.

Quick Verdict

Treat this as a split decision. Claude Haiku 4.5 makes more sense if you would rather avoid the extra latency and token burn of a reasoning model; Composer 2 is the better fit if agentic is the priority or you want the cheaper token bill.

Agentic

Composer 2

Claude Haiku 4.5

51.9

Composer 2

61.7

41%
Terminal-Bench 2.0
61.7%
62%
BrowseComp
Coming soon
57%
OSWorld-Verified
Coming soon

Coding

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

60%
HumanEval
Coming soon
73.3%
SWE-bench Verified
Coming soon
46%
SWE-bench Pro
Coming soon
23%
FLTEval
Coming soon
Coming soon
SWE Multilingual
73.7%
Coming soon
React Native Evals
97.2%

Multimodal & Grounded

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

82%
MMMU-Pro
Coming soon
74%
OfficeQA Pro
Coming soon

Reasoning

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

63%
MuSR
Coming soon
81%
BBH
Coming soon
72%
LongBench v2
Coming soon
70%
MRCRv2
Coming soon

Knowledge

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

68%
MMLU
Coming soon
67%
GPQA
Coming soon
65%
SuperGPQA
Coming soon
73%
MMLU-Pro
Coming soon
11%
HLE
Coming soon
64%
FrontierScience
Coming soon
65%
SimpleQA
Coming soon

Instruction Following

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

86%
IFEval
Coming soon

Multilingual

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

82%
MGSM
Coming soon
79%
MMLU-ProX
Coming soon

Mathematics

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

68%
AIME 2023
Coming soon
70%
AIME 2024
Coming soon
69%
AIME 2025
Coming soon
64%
HMMT Feb 2023
Coming soon
66%
HMMT Feb 2024
Coming soon
65%
HMMT Feb 2025
Coming soon
67%
BRUMO 2025
Coming soon
81%
MATH-500
Coming soon

Frequently Asked Questions

Which is better, Claude Haiku 4.5 or Composer 2?

Claude Haiku 4.5 and Composer 2 are tied on overall score, so the right pick depends on which category matters most for your use case.

Which is better for agentic tasks, Claude Haiku 4.5 or Composer 2?

Composer 2 has the edge for agentic tasks in this comparison, averaging 61.7 versus 51.9. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

Last updated: March 18, 2026

Weekly LLM Benchmark Digest

Get notified when new models drop, benchmark scores change, or the leaderboard shifts. One email per week.

Free. No spam. Unsubscribe anytime. We only store derived location metadata for consent routing.