Claude Haiku 5.5 vs Opus 5.5
Last updated: October 8, 2026
Claude Haiku 5.5 costs 40x less than Claude Opus 5.5 for both input and output at Claude Haiku 5.5's ≤100k prompt tier: $0.10 vs $4 input and $0.50 vs $20 output per million tokens. Cache reads are 20x apart at $0.01 vs $0.20.[1][2]
The premium shows most clearly in complex work. Opus 5.5 leads Terminal-Bench 4.0 by 66.4% to 39.2% and GDPval-AA v2.1 by 1846 to 1620. Anthropic's own deployment pattern is therefore more useful than a winner/loser verdict: Opus or Sonnet as the primary model, with Haiku 5.5 handling bounded coding work as a subagent.[1][2]
The verdict in 30 seconds
High-frequency work
Use Haiku 5.5 for narrow, repeated, cost-sensitive tasks. At the ≤100k tier, input and output each cost one-fortieth of Opus 5.5.
Complex execution
Pay for Opus 5.5 when multi-step agentic coding, codebase-wide work, computer use, or high-value knowledge work makes errors expensive.
Long-running agents
Use a mixed system: Opus or Sonnet as the primary model, with Haiku 5.5 taking frequent, bounded subagent calls.
At a glance
| Dimension | Claude Haiku 5.5 | Claude Opus 5.5 |
|---|---|---|
| Input price (per 1M tokens) | $0.10 (prompt ≤100k) / $0.50 (prompt >100k) | $4 |
| Output price (per 1M tokens) | $0.50 (prompt ≤100k) / $2.50 (prompt >100k) | $20 |
| Cache writes (per 1M tokens) | $0.125 (prompt ≤100k) / $0.625 (prompt >100k) | $5 |
| Cache reads (per 1M tokens) | $0.01 (prompt ≤100k) / $0.05 (prompt >100k) | $0.20 |
| GDPval-AA v2.1 (knowledge work) | 1620 | 1846 |
| Terminal-Bench 4.0 (agentic coding) | 39.2% | 66.4% |
| FrontierCode v1.1 (Main) | 46.4% | 54.4% |
| Humanity's Last Exam (with tools) | 57.4% | 67.7% |
| Positioning | High-frequency, low-cost work and coding subagent tasks | Complex agentic coding and high-value knowledge work |
Pricing and scores come from Anthropic's official model pages.[1][2] Both Humanity's Last Exam figures use the tool-enabled setting. The reported effort settings are not fully matched: Anthropic specifies xhigh effort for Opus 5.5 Terminal-Bench 4.0, while the Haiku 5.5 page does not specify an effort setting. Anthropic's Opus table gives FrontierCode as 54.4%; its prose separately reports 54.6% at default (medium) effort. Chartography and OSWorld are omitted because the published settings differ and are not directly comparable.
How Anthropic positions Haiku 5.5 and Opus 5.5
“Claude Sonnet 5.5 and Claude Haiku 5.5 will follow in the coming weeks, with many of the same improvements to performance, efficiency, and safety.”[2]
That made Opus 5.5 the first model released in the Claude 5.5 family. Haiku 5.5's release then made the intended relationship explicit:
“It pairs well with Opus 5.5 and Sonnet 5.5 as a subagent on coding work.”[1]
Anthropic itself presents Haiku 5.5 as a subagent that pairs with Opus 5.5 and Sonnet 5.5, rather than simply positioning the models as substitutes. For long-running agents, that supports a mixed architecture: Opus or Sonnet as the primary model, with frequent, lower-cost subagent work routed to Haiku 5.5.
Haiku 5.5, in detail
Haiku 5.5 is the rational default for large volumes of repeated work with a narrow definition of done. Anthropic specifically names summaries, compactions, database queries, and classification requests, alongside its coding-subagent role.[1] Those workloads can use the $0.10 input, $0.50 output, and $0.01 cache-read rates at the ≤100k prompt tier instead of paying the Opus premium.
Its scores show where that economy has limits. Haiku 5.5 reaches 1620 on GDPval-AA and 39.2% on Terminal-Bench 4.0: useful capability for a small tier, but behind Opus 5.5 on knowledge work and especially agentic coding. The full official score set is collected in the Claude Haiku 5.5 benchmark table.
Anthropic says Haiku 5.5 is about 75% cheaper to run than Haiku 4.5, after accounting for tokenizer changes that slightly increase tokens per task.[1] See the Claude Haiku 5.5 pricing breakdown for both prompt-length tiers.
Opus 5.5, in detail
Opus 5.5 earns its premium when the task needs stronger multi-step execution: complex agentic coding, codebase migrations and audits, computer use, or high-value knowledge work. The largest shared gap in this comparison is Terminal-Bench 4.0, where Opus reports 66.4% against Claude Haiku 5.5's 39.2%; GDPval-AA is 1846 against 1620.[1][2]
Compared with Opus 5, Anthropic prices Opus 5.5 input and output 20% lower and cache reads 60% lower, estimates a typical workload at about 40% less, and reports output speed improved by more than 30%.[2] The premium should therefore be reserved for work where capability and error cost matter more than call volume.
Opus 5.5 Fast mode is available in Claude Code and on the Claude Platform, reaches up to 2.5x speed, and has separate pricing of $8 input and $40 output per million tokens.[2] Those rates are distinct from standard Opus 5.5 pricing. Teams choosing a middle tier can also review Claude Sonnet 5.5.
When to use which
- Use Haiku 5.5 for narrow-scope, high-frequency, cost-sensitive tasks: summaries, compactions, database queries, and classification requests.
- Use Opus 5.5 for complex multi-step agentic coding, codebase-level migrations and audits, computer use, and high-value knowledge work.
- Use a mixed model system for long-running agents: Opus or Sonnet as the primary model, plus Haiku 5.5 as the subagent. That puts frequent calls on the lower-cost tier while reserving the stronger model for complex decisions.
Cost at scale
For one million input tokens plus one million output tokens, Haiku 5.5 costs $0.60: $0.10 input plus $0.50 output. Opus 5.5 costs $24.00: $4 input plus $20 output. The same token mix therefore costs 40x more on Opus 5.5.[1][2]
| Model | Input | Output | Total |
|---|---|---|---|
| Claude Haiku 5.5 | $0.10 | $0.50 | $0.60 |
| Claude Opus 5.5 | $4.00 | $20.00 | $24.00 |
This example uses Haiku 5.5's ≤100k pricing tier. It compares known token prices only; it does not assume throughput, concurrency, cache hit rate, or a typical agent's token consumption.
Not yet confirmed under shared test conditions: real TPS, rate limits, context windows, and Haiku 5.5 benchmark scores by effort level.
Frequently asked questions
Is Haiku 5.5 good enough to replace Opus 5.5?
Not as a blanket replacement. Haiku 5.5 fits high-frequency, narrow, cost-sensitive work; Opus 5.5 fits complex agentic coding, codebase-level work, computer use, and high-value knowledge work. Anthropic explicitly positions Haiku 5.5 as a coding subagent that pairs with Opus 5.5 and Sonnet 5.5, so the official framing is division of labor rather than substitution.
How much cheaper is Haiku 5.5 than Opus 5.5?
At Haiku 5.5's ≤100k prompt tier, Opus 5.5 costs 40x more for input ($4 vs $0.10 per million tokens), 40x more for output ($20 vs $0.50), and 20x more for cache reads ($0.20 vs $0.01).
Can Haiku 5.5 be used as a subagent for Opus 5.5?
Yes. Anthropic says Haiku 5.5 pairs well with Opus 5.5 and Sonnet 5.5 as a subagent on coding work. That makes it a documented option for bounded, high-frequency calls inside an agent driven by a larger primary model.
Which is faster, Haiku 5.5 or Opus 5.5?
Not yet confirmed under a shared test. Anthropic positions Haiku 5.5 as its fastest model and says Opus 5.5 has 30%+ faster output than Opus 5, but it does not publish matched-condition TPS figures for Haiku 5.5 versus Opus 5.5. Opus 5.5 Fast mode can reach up to 2.5x speed at separate pricing.
Should I move from Opus 5 to Opus 5.5?
The confirmed changes favor Opus 5.5: input and output prices are 20% lower, cache reads are 60% lower, Anthropic estimates typical workloads cost about 40% less, and output is 30%+ faster. Those are the supported migration benefits; the decision still depends on your own workload and evaluation.
Sources
- Anthropic — Claude Haiku 5.5 (official release page) Published October 7, 2026; source for Claude Haiku 5.5 pricing, positioning, and benchmark figures.
- Anthropic — Claude Opus 5.5 (official release page) Published September 22, 2026; source for Opus pricing, positioning, Fast mode, and benchmark figures.
Every product fact and number on this page comes from Anthropic's official Claude Haiku 5.5 and Claude Opus 5.5 pages. Differing test settings are labeled rather than treated as direct comparisons.
Last updated: October 8, 2026