Claude Haiku 5.5 vs Sonnet 5.5 vs Opus 5.5: Price, Speed, Uses

Claude Haiku 5.5 is the cheapest and fastest of the three, starting at $0.10 per million input tokens and $0.50 per million output tokens for prompts under 100,000 tokens. Claude Sonnet 5.5 costs $2 and $10 per million input/output tokens and is Anthropic's "fast" tier for everyday coding and knowledge work. Claude Opus 5.5 costs $4 and $20 per million input/output tokens and is built for long, complex agentic work. All three now share a 1 million-token context window and a 128,000-token standard output limit, according to Anthropic's own model-comparison table. With Haiku 5.5's October 7, 2026 release, the Claude 5.5 lineup — Opus 5.5 (September 22), Sonnet 5.5 (September 28), and Haiku 5.5 (October 7) — is complete for the first time, giving developers a full small/medium/large set to choose from on price, speed, and task complexity.

The Claude 5.5 Family Is Now Complete

Anthropic rolled out its 5.5 generation in three steps over sixteen days. Claude Opus 5.5 launched first, on September 22, 2026, positioned for long-running agentic coding and knowledge work. Claude Sonnet 5.5 followed on September 28, 2026, as a faster, similarly priced upgrade to Sonnet 5. Claude Haiku 5.5 arrived last, on October 7, 2026, completing the set as what Anthropic describes as its fastest, cheapest, and most capable small model to date. That sequencing — largest model first, smallest last — matches how Anthropic has staged previous generations, but this is the first time the full 5.5 family has been available simultaneously, which is why the comparison question now actually has three real answers instead of two.

Anthropic's own model overview page now lists Opus 5.5, Sonnet 5.5, and Haiku 5.5 side by side alongside the separate reasoning-focused Claude Fable 5.1. That table is the cleanest single source for how Anthropic itself wants the three positioned, and it's the basis for most of the comparisons below.

Claude Haiku 5.5 vs Sonnet 5.5 vs Opus 5.5: Pricing

All three models are priced per million tokens, with separate input and output rates. Haiku 5.5 is the only one of the three with a two-tier price structure based on prompt length.

Anthropic's official pricing page confirms the same per-token rates and adds batch-processing (50% off) and prompt-caching details for all three models. On a pure per-token basis, Opus 5.5 costs 40x more than Haiku 5.5's lowest tier for input and 40x more for output. Sonnet 5.5 sits in between at a flat $2/$10. Anthropic's own Claude Haiku 5.5 announcement says the new small model runs about 75% cheaper on average than Haiku 4.5 once you account for actual workloads — roughly 90% cheaper for requests under 100,000 tokens and 50% cheaper above that threshold, since the higher tier kicks in. Sonnet 5.5 kept the exact same headline rate as Sonnet 5 ($2 input / $10 output), but Anthropic says it typically uses fewer tokens per completed task, which it estimates brings real-world cost down by up to 30%. Opus 5.5 dropped its sticker price from Opus 5's $5/$25 to $4/$20 — about a 20% rate cut that Anthropic says translates to roughly 40% lower cost on typical workloads at default settings, because the model also needs fewer tokens to finish the same work.

Cache pricing scales with the same ratios: Haiku 5.5 cache reads are $0.01–$0.05 per million tokens depending on tier, Sonnet 5.5 is $0.10, and Opus 5.5 is $0.20. Prompt caching matters most for Opus 5.5 and Sonnet 5.5, where repeated large contexts (codebases, long documents) are common; it matters less for Haiku 5.5, which is usually called on shorter, more disposable prompts. Opus 5.5 also has a Fast Mode, available in Claude Code and the Claude Platform, that doubles the base rate to $8/$40 in exchange for up to 2.5x faster responses — effectively a fourth price point for teams that need Opus-level reasoning without Opus-level wait times.

For a deeper breakdown of how Opus 5.5 and Sonnet 5.5 pricing played out before Haiku 5.5 existed, see Pandromeda's earlier Opus 5.5 vs Sonnet 5.5 comparison; the per-token numbers for those two models haven't changed, but Haiku 5.5 now gives budget-conscious teams a third, much cheaper option that didn't exist when that piece published.

Context Window and Output Limits

This is the one spec where Anthropic drew no distinction between the three models. According to the official Claude model comparison table, Claude Haiku 5.5, Claude Sonnet 5.5, and Claude Opus 5.5 all support a 1 million-token context window and a 128,000-token maximum output on the standard Messages API. All three also support up to 300,000 output tokens through the Message Batches API beta (header output-300k-2026-03-24). In practical terms, that means the choice between models is not a choice about how much text or code you can feed in or get back — it's a choice about cost per token and how much reasoning depth you need for a given task.

That parity is new. In earlier Claude generations, Haiku-class models were capped at a smaller context window than Sonnet and Opus. Anthropic's own documentation notes that models before the tokenizer introduced with Claude Opus 4.7 fit roughly 750,000 words into 1M tokens, versus about 555,000 words on the current tokenizer — a reminder that "1M tokens" is not a fixed amount of English text and shifts slightly between tokenizer generations.

Speed and Latency Class

Anthropic's model overview table ranks the current four-model lineup by "comparative latency" as: Claude Fable 5.1 (Slower), Claude Opus 5.5 (Moderate), Claude Sonnet 5.5 (Fast), and Claude Haiku 5.5 (Fastest). That ranking is relative within Anthropic's own current lineup, not an absolute benchmark, and the company is explicit that actual latency depends heavily on prompt length, output length, and the effort level you choose.

Each model's own launch post adds a same-generation comparison: Sonnet 5.5 generates output "more than 30% faster" than Sonnet 5, and Opus 5.5 generates output "more than 30% faster" than Opus 5, with Anthropic attributing part of that gain to Opus 5.5 needing less compute to serve. Anthropic hasn't published a same-generation percentage for Haiku 5.5's speed versus Haiku 4.5 directly comparable to those two figures; instead it describes Haiku 5.5 as its fastest model to date at each model's standard speed, with reported customer results (not Anthropic's own benchmark) showing latency reductions of 30% to roughly 50% depending on the workload. All three models support an adjustable effort parameter (Low, Medium, High, Xhigh, Max) that trades speed and token usage for answer quality — Haiku 5.5 and Opus 5.5 default to Medium effort, while Sonnet 5.5 defaults to High.

Opus 5.5's Fast Mode is worth calling out separately: it's a paid option, not a free speed boost, doubling the per-token rate to buy up to 2.5x faster responses in Claude Code and the Claude Platform specifically. There's no equivalent fast mode for Sonnet 5.5 or Haiku 5.5 — their speed advantage over Opus 5.5 is already built into the base price.

Best-Fit Use Cases for Each Model

Anthropic's own positioning language for the three models is fairly consistent across its launch posts and documentation:

• Claude Haiku 5.5 — described for "high-volume, latency-sensitive tasks such as classification, extraction, and routing." Anthropic also calls out summarization, context compaction, database queries, subagent work underneath a Sonnet or Opus "lead" model, live customer support, and browser use as good fits. It's the first Haiku-class model with an adjustable effort setting, letting teams dial up quality for harder sub-tasks without switching models entirely.
• Claude Sonnet 5.5 — described as "the best combination of speed and intelligence." Anthropic points to well-scoped everyday coding and bug fixes, polished documents, slides and spreadsheets, UI/design work, multi-step agentic coding, and knowledge work such as financial analysis and support-ticket handling.
• Claude Opus 5.5 — described as built "for long-running agentic coding and knowledge work." Anthropic specifically names large codebase migrations and audits, computer use, open-ended research reports and financial analysis, and — through its verification programs — biology research and cybersecurity work by vetted organizations and practitioners.

If you're deciding between Sonnet 5.5 and Opus 5.5 specifically for a coding workflow, it's also worth reading how Claude's models fit into actual coding tools: Pandromeda's guide to Claude Code, Anthropic's AI coding agent, explains how model choice interacts with that product, and a separate piece compares Claude Code pricing against Cursor, GitHub Copilot, and Codex for teams weighing coding-assistant costs rather than raw API pricing.

What Anthropic's Own Benchmarks Show

Anthropic publishes internal benchmark results on each model's launch page, and it's worth being precise about what they actually show rather than rounding up. On Terminal-Bench 4.0 — Anthropic's agentic-coding evaluation — the company's own published figures are: Claude Haiku 5.5 at 39.2%, Claude Sonnet 5.5 at 70.6%, and Claude Opus 5.5 at 66.4% at its highest ("Xhigh") effort setting. Those numbers are consistent across both the Sonnet 5.5 and Opus 5.5 launch pages, which is one reason to trust the comparison on this specific benchmark more than others where the two launch posts report slightly different figures for the same model (a sign that different benchmark subsets or effort settings were used, which Anthropic doesn't always fully reconcile between posts).

The notable detail is that Sonnet 5.5 outscores Opus 5.5 on Terminal-Bench 4.0 at the effort levels Anthropic chose to publish — a reminder that "bigger model" doesn't automatically mean "higher benchmark score" once effort settings and task type are factored in. Anthropic itself cautions that benchmark margins are "a less reliable guide to real-world differences" at this capability level, and that its published scores reflect maximum effort unless stated otherwise. Haiku 5.5's own launch page is franker still, stating plainly that Sonnet 5.5 and Opus 5.5 remain the better choice for complex agentic coding, and that Haiku 5.5 is intended for narrower, previously-too-expensive tasks like compaction, summarization, and subagent work rather than head-to-head competition on coding benchmarks.

None of Anthropic's three launch posts publish a single apples-to-apples table with all three models on identical benchmark subsets at matched effort levels, so treat any single-number "best model" claim — including ones circulating from leaked or unofficial sources — with skepticism until Anthropic publishes one directly.

Claude Haiku 5.5 in Detail

Beyond price and speed, Claude Haiku 5.5's most distinctive feature is being the first Haiku-class model with an adjustable effort parameter, the same Low/Medium/High/Xhigh/Max scale Anthropic uses on Sonnet and Opus. That lets a developer route a task to Haiku 5.5 by default and only pay for higher effort — and higher latency — on the subset of requests that actually need it, rather than switching to a larger model entirely. Anthropic also added beta computer-use and browser-use support to its Python and TypeScript SDKs alongside the Haiku 5.5 release, reflecting the model's intended role running inside agent pipelines rather than as a standalone chat assistant. The model ID for API calls is claude-haiku-5-5, available on the Claude Platform, Amazon Web Services, Google Cloud, and Microsoft Azure from launch.

Claude Sonnet 5.5 and Opus 5.5 in Detail

Sonnet 5.5 (API model ID claude-sonnet-5-5) kept Sonnet 5's exact price but cut its prompt-cache read cost in half, from $0.20 to $0.10 per million tokens, which Anthropic says makes it roughly 20% cheaper on most agentic work even before accounting for the token-efficiency gains. It ships with zero-data-retention options and is available on the Claude Platform, AWS, Google Cloud, and Microsoft Azure.

Opus 5.5 (API model ID claude-opus-5-5) is the only one of the three built with dedicated verification-program access: the Life Sciences Verification Program for vetted biology research organizations, and an expanding Cyber Verification Program for verified cybersecurity practitioners, both gating access to higher-capability, higher-risk use of the model. Anthropic also specifically cites Opus 5.5's "clearer writing" as an advantage for long working sessions, on the theory that outputs a human can actually follow and check are more valuable than raw capability during multi-hour agentic runs.

Which Should You Use Next?

For most new projects, start by testing Claude Sonnet 5.5 — it's the model Anthropic positions as the default balance of capability and cost, and at $2/$10 per million tokens it's cheap enough to prototype with before committing. Route high-volume, low-complexity steps in the same pipeline — classification, extraction, summarization, subagent calls — to Claude Haiku 5.5, where the price difference (as low as $0.10 input / $0.50 output) is large enough to change your unit economics outright. Reserve Claude Opus 5.5 for the narrower set of tasks where you've already found that Sonnet 5.5 isn't accurate enough: large, multi-file codebase migrations, long autonomous agent runs, or research and financial-analysis work where getting the answer right matters more than the per-token bill. Because all three models now share the same 1M-token context window, you can move a task between models based purely on cost and quality needs without rewriting your prompts around a smaller context limit — something that wasn't true of earlier Haiku generations.

Written byTheo Park

Theo Park runs the AI desk at Pandromeda. He follows model launches from the frontier labs and the open-weight community, tracks the assistants and developer tools built on them, and explains what each release changes on pricing, capability and safety. His reporting leans on primary sources: model cards, technical reports, API documentation and the companies' own announcements.

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