Skip to content
ModelCap

Head-to-head comparison

Claude Haiku 4.5 vs Claude Opus 5.5

Claude Haiku 4.5 (Anthropic) and Claude Opus 5.5 (Anthropic) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.

Snapshot as of 22 September 2026

As of 22 September 2026, Claude Opus 5.5 holds the stronger ModelCap Index position (#1 vs #69); Claude Haiku 4.5 is 4× cheaper per output token ($5.00/1M vs $20.00/1M); and Claude Opus 5.5 offers the longer context window (1M vs 200K tokens).

Which should you choose?

Choose Claude Haiku 4.5 if…

  • API cost matters — $5.00/1M output tokens against $20.00/1M, about 4× cheaper.
  • your workload is prompt-heavy — input tokens cost $1.00/1M against $4.00/1M.

Choose Claude Opus 5.5 if…

  • you want the stronger overall ModelCap Index position — #1 against #69 (98.6 vs 61.3 points).
  • you need the longer context window — 1M tokens against 200K.
  • you want provider choice — 5 listed API providers against 4.
  • ARC-AGI-2 is your yardstick — 93.3% against 4.0%.
  • you want the more recently listed model — Claude Opus 5.5 was listed 22 September 2026, Claude Haiku 4.5 15 October 2025.

Claude Haiku 4.5 vs Claude Opus 5.5: specs, pricing and context

Specification comparison of Claude Haiku 4.5 and Claude Opus 5.5
FieldClaude Haiku 4.5AnthropicClaude Opus 5.5Anthropic
ModelCap Index position#69#1
Index score61.398.6
EvidenceMeasuredMeasured
Input price / 1M tokens$1.00$4.00
Output price / 1M tokens$5.00$20.00
Context window200K tokens1M tokens
Max output tokens64K128K
API providers listed45
Weight accessAPI onlyAPI only
Input modalitiesText, Image, FileText, Image, File
First listed15 October 202522 September 2026
PublisherAnthropicAnthropic

Evidence: 3 public benchmark observations across 3 boards · 2 public benchmark observations across 2 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: Claude Haiku 4.5 vs Claude Opus 5.5

Public benchmark boards where Claude Haiku 4.5 or Claude Opus 5.5 has a published result
BoardClaude Haiku 4.5Claude Opus 5.5Leads
Arena codingArena (LMArena)14821477–1486—Only one result
ARC-AGI-2ARC Prize Foundation4.0%Thinking93.3%HighClaude Opus 5.5
SWE-benchSWE-bench (Princeton / SWE-agent team)66.6%High—Only one result
BFCL V4UC Berkeley (Gorilla)68.7Function calling—Only one result
AA Intelligence IndexArtificial Analysis—57.6intelligence-index:v4.3:reasoning-unspecifiedOnly one result
AA Humanity's Last ExamArtificial Analysis—61.4%hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="Claude Opus 5.5 (Adaptive Reasoning, Max Effort, Default Fallback)":reasoning=trueOnly one result

Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.

Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.

Claude Haiku 4.5 vs Claude Opus 5.5: common questions

Is Claude Haiku 4.5 better than Claude Opus 5.5?

Claude Opus 5.5 ranks higher on the ModelCap Index as of 22 September 2026: #1 against #69. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it. Their published uncertainty intervals do not overlap, but the aggregate Index does not predict performance on every task; compare the relevant benchmark configurations before choosing.

Is Claude Haiku 4.5 cheaper than Claude Opus 5.5?

Claude Haiku 4.5 is cheaper on output tokens: $5.00/1M against $20.00/1M. Input tokens are $1.00/1M for Claude Haiku 4.5 and $4.00/1M for Claude Opus 5.5. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens. For 1,000 requests with 2,000 input and 500 output tokens each (2M input + 0.5M output), the listed-rate estimate is $4.50 for Claude Haiku 4.5 versus $18.00 for Claude Opus 5.5. Claude Haiku 4.5 costs 75.0% less in this scenario. This excludes caching, batch discounts, prompt-length tiers, tool charges and retries; verify the selected endpoint before budgeting.

Which has the bigger context window, Claude Haiku 4.5 or Claude Opus 5.5?

Claude Opus 5.5 has the larger context window: 1M tokens against 200K.

Which is better for coding, Claude Haiku 4.5 or Claude Opus 5.5?

The two models do not share a coding benchmark board on ModelCap yet, so no head-to-head coding score is published; the ModelCap Index position is the closest overall signal.

Are Claude Haiku 4.5 and Claude Opus 5.5 open-weight models?

Claude Haiku 4.5: API only. Claude Opus 5.5: API only. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.

Where can I run Claude Haiku 4.5 and Claude Opus 5.5?

ModelCap currently lists 4 API providers for Claude Haiku 4.5 and 5 for Claude Opus 5.5, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this Claude Haiku 4.5 vs Claude Opus 5.5 comparison?

Every figure comes from the sealed ModelCap dataset published 22 September 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.

Explore further