HEAD-TO-HEAD · MID-TIER · VERIFIED SEPTEMBER 14, 2026

Claude Haiku 4.5 vs Claude Sonnet 5: which is actually cheaper?

Claude Haiku 4.5 and Claude Sonnet 5 are Anthropic's mid-tier models, separated by a clean 2× price gap. Haiku costs $1 input / $5 output per million tokens, while Sonnet 5 costs $2 input / $10 output. Both models are active in September 2026.

Spec	Claude Haiku 4 5	Claude Sonnet 5
Input / 1M tokens	$1.00	$2.00
Output / 1M tokens	$5.00	$10.00
Context window	200K (estimated)	200K (estimated)

The output price gap

The output pricing gap between these models is exactly 2×: Haiku 4.5 charges $5 per million output tokens while Sonnet 5 charges $10. Since output tokens typically dominate real-world LLM costs—especially for generation-heavy tasks like coding, content creation, or long-form assistants—this 2× multiplier compounds quickly at scale. For every 10 million output tokens, Haiku saves you $50 compared to Sonnet 5. The input gap mirrors this ratio: $1 versus $2 per million tokens.

Context window

Both models support an estimated 200K token context window, though Anthropic has not published definitive context limits for the Claude 5-series models at the time of writing. This estimate aligns with typical mid-tier model capabilities in 2026. If your use case requires confirmed context specifications, consult Anthropic's official documentation or contact their support team, as real limits may vary by deployment environment and may be subject to change.

Worked example

At a realistic monthly workload of 100 million input tokens and 30 million output tokens, Haiku 4.5 costs (100M × $1/M) + (30M × $5/M) = $100 + $150 = $250 per month. Sonnet 5 at the same volume costs (100M × $2/M) + (30M × $10/M) = $200 + $300 = $500 per month. That's a $250 monthly difference, or exactly 2× the cost for Sonnet 5. For output-heavy workloads the gap widens further; for input-heavy workloads it narrows slightly.

Prices from the LLM Price Watch daily tracker, September 14, 2026. Prices change; use the calculator with your own usage for an exact comparison, or see the full price table for every tracked model.

Frequently asked questions

Which model should I choose for high-volume classification or extraction tasks?

Haiku 4.5 is designed specifically for high-volume, latency-sensitive workloads like classification, extraction, routing, and short chat turns. At $1 input / $5 output per million tokens, it absorbs bulk traffic at half the cost of Sonnet 5 while maintaining fast response times. Reserve Sonnet 5 for tasks requiring deeper reasoning or synthesis.

Does Sonnet 5 justify the 2× price premium over Haiku 4.5?

Sonnet 5 is Anthropic's everyday-tier model for general-purpose work involving reasoning, synthesis, structured writing, and multi-constraint answers. If your task requires more than simple extraction or classification—such as coding assistance, complex instructions, or multi-step analysis—Sonnet 5's capability gains often justify the 2× cost premium over Haiku 4.5.

Can I mix Haiku 4.5 and Sonnet 5 to optimize costs?

Yes, model routing is one of the most effective cost optimization strategies. Route routine, high-volume requests to Haiku 4.5 and escalate complex tasks to Sonnet 5 (or higher tiers like Opus 5). This hybrid approach lets you balance cost and capability dynamically based on each request's complexity, maximizing value across your workload.

Are there additional discounts or pricing modifiers I should know about?

Both models support prompt caching, which cuts input costs by up to 90% on repeated context (cache hits cost 10% of base input). The Batch API offers a flat 50% discount on both input and output for non-urgent workloads. Combining routing, caching, and batch processing can reduce total spend significantly below the standard per-token rates.