Claude Haiku 5.5 vs Claude Sonnet 4.6
Anthropic · US | Anthropic · US · Updated June 2026
Quick verdict
Both are Anthropic models. Claude Haiku 5.5 is the newer, generally stronger default; reach for Claude Sonnet 4.6 when a specific cost or latency profile matters more than the latest capabilities.
Claude Haiku 5.5 and Claude Sonnet 4.6 are both Anthropic models, so the real question is not which lab to trust but which tier fits your workload and budget. Claude Haiku 5.5 is anthropic's October 7, 2026 small-model refresh — a 1M-token context window (up from 200K) at roughly 75% lower average cost than Haiku 4.5, priced at $0.10/$0.50 per million tokens. Claude Sonnet 4.6 is opus-class quality at lower cost; superseded as the default Sonnet by Claude Sonnet 5 (June 2026). Since both come from the same lab, the comparison below focuses on the tier-and-cost trade-offs that actually separate them.
Key differences at a glance
- ▸Price: Claude Haiku 5.5 is about 30× cheaper on input ($0.1/$0.5 per 1M tokens vs $3/$15 per 1M tokens) — a large enough gap that at scale it can be the single biggest line item in the decision.
- ▸Context window: both advertise 1M tokens (~1,500 pages). Tie on paper — test on your own long inputs, since usable recall varies by model.
- ▸Recency: Claude Haiku 5.5 is the newer model by about 8 months (released October 7, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
| Spec | Claude Haiku 5.5 | Claude Sonnet 4.6 |
|---|---|---|
| Provider | Anthropic (US) | Anthropic (US) |
| Released | October 7, 2026 | February 17, 2026 |
| Context window | 1M tokens (~1,500 pages) | 1M (~1,500 pages) |
| Price (in/out) | $0.1/$0.5 per 1M tokens | $3/$15 per 1M tokens |
| Open weight? | No — API only | No — API only |
| Modalities | text, image, code | text, image, code |
| SWE-Bench Verified | Not published | 79.6% |
| MRCR v2 @ 1M | Not published | Not published |
Who wins what
5x the context window of Haiku 4.5 (1M vs 200K tokens) and double the max output (128K vs 64K)
Claude Haiku 5.5
Anthropic's October 7, 2026 small-model refresh — a 1M-token context window (up from 200K) at roughly 75% lower average cost than Haiku 4.5, priced at $0.10/$0.50 per million tokens — and it runs cheaper at $0.1/$0.5 per 1M tokens.
First Haiku-class model with an adjustable 'effort' setting to trade off cost, latency, and intelligence
Claude Haiku 5.5
At $0.1/$0.5 per 1M tokens it undercuts Claude Sonnet 4.6 ($3/$15 per 1M tokens), and that gap compounds at volume.
Anthropic's cheapest small model yet — runs about 75% cheaper on average than Haiku 4.5
Claude Haiku 5.5
Anthropic's October 7, 2026 small-model refresh — a 1M-token context window (up from 200K) at roughly 75% lower average cost than Haiku 4.5, priced at $0.10/$0.50 per million tokens — and it is the newer of the two.
Best value in the Claude family
Claude Sonnet 4.6
Claude Sonnet 4.6 lists best value in the Claude family among its strengths; Claude Haiku 5.5 does not.
Everyday professional work
Claude Sonnet 4.6
Claude Sonnet 4.6 lists everyday professional work among its strengths; Claude Haiku 5.5 does not.
Long-document analysis
Claude Sonnet 4.6
Claude Sonnet 4.6 lists long-document analysis among its strengths; Claude Haiku 5.5 does not.
Lowest cost at scale
Claude Haiku 5.5
At $0.1/$0.5 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Which should you pick?
A cost-sensitive startup shipping high volume
→ Claude Haiku 5.5
At $0.1/$0.5 per 1M tokens it undercuts Claude Sonnet 4.6, and on millions of tokens that margin decides the monthly bill.
Anyone whose priority is 5x the context window of haiku 4.5 (1m vs 200k tokens) and double the max output (128k vs 64k)
→ Claude Haiku 5.5
It is specifically built for that.
Anyone whose priority is best value in the claude family
→ Claude Sonnet 4.6
That is its strongest area.
Claude Haiku 5.5: where it fits
Anthropic's October 7, 2026 small-model refresh — a 1M-token context window (up from 200K) at roughly 75% lower average cost than Haiku 4.5, priced at $0.10/$0.50 per million tokens. Released October 7, 2026 by Anthropic, it is built for 5x the context window of Haiku 4.5 (1M vs 200K tokens) and double the max output (128K vs 64K), first Haiku-class model with an adjustable 'effort' setting to trade off cost, latency, and intelligence, anthropic's cheapest small model yet — runs about 75% cheaper on average than Haiku 4.5, and over-refuses benign requests only 0.17% of the time on the API, down from Haiku 4.5's 0.44%.
Its trade-offs are real: pricing jumps roughly 5x beyond 100K-token prompts ($0.50/$2.50 per million vs the headline $0.10/$0.50), extended thinking can no longer be fully disabled — only dialed between low, medium, and high effort, and as the smallest tier, trails both Sonnet 5.5 and Opus 5.5 on hard reasoning and open-ended work. At $0.1 in / $0.5 out per million tokens, it sits in the budget price band.
Claude Sonnet 4.6: where it fits
Opus-class quality at lower cost; superseded as the default Sonnet by Claude Sonnet 5 (June 2026). Released February 17, 2026 by Anthropic, it is built for best value in the Claude family, everyday professional work, long-document analysis, and coding at lower cost than Opus.
Its trade-offs: trails Opus on the hardest agentic tasks, and not an open-weight option. At $3 in / $15 out per million tokens, it sits in the mid price band.
The bottom line for this matchup
Because Claude Haiku 5.5 and Claude Sonnet 4.6 come from the same lab (Anthropic), they share the same training philosophy and ecosystem — the decision is purely tier vs. cost. Claude Haiku 5.5 is the more capable, more recent option; the other earns its place only when its price or latency profile fits a specific job better. Most teams should default to Claude Haiku 5.5 and drop down only with a concrete reason.
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See pricingFrequently asked questions
Is Claude Haiku 5.5 or Claude Sonnet 4.6 better for coding?
Public SWE-Bench figures are not available for Claude Haiku 5.5, so the honest test is your own repository — run an identical real bug through both. By design, Claude Haiku 5.5 leans toward 5x the context window of haiku 4.5 (1m vs 200k tokens) and double the max output (128k vs 64k) while Claude Sonnet 4.6 leans toward best value in the claude family, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Claude Haiku 5.5 or Claude Sonnet 4.6?
Claude Haiku 5.5 is cheaper — $0.1/$0.5 per 1M tokens vs $3/$15 per 1M tokens, roughly 30× apart on input.
Which has the bigger context window?
Both advertise 1M tokens (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.
Should I upgrade from Claude Sonnet 4.6 to Claude Haiku 5.5?
Since both are Anthropic models, the newer one (Claude Haiku 5.5) is usually the better default unless you need a specific cost or latency profile from the other.
Which is newer, Claude Haiku 5.5 or Claude Sonnet 4.6?
Claude Haiku 5.5 — released October 7, 2026, about 8 months after Claude Sonnet 4.6.
Related comparisons
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.