AI model comparison

Claude Haiku 4.5 vs GPT-5 mini

Comparing two fast, lower-cost models for high-volume classification, routing, and lightweight extraction where latency and unit price matter most.

Quick answer: GPT-5 mini lists the lower prices ($0.25/$2 per 1M versus $1/$5) and the larger context window (400k versus 200k); Claude Haiku 4.5 is positioned as the quality-stronger small tier at a higher list price.

Pricing & context

All figures below are list prices pulled directly from the Harpd pricing registry (last verified 2026-08-18). Prices change often — open each model’s source link to confirm before budgeting. Machine-readable copy: /data/llm-pricing.json.

MetricClaude Haiku 4.5GPT-5 mini
ProviderAnthropicOpenAI
Input / 1M tokens$1$0.25
Output / 1M tokens$5$2
Cached input / 1M tokens$0.1$0.03
Batch discount50% off50% off
Context window200,000 tokens400,000 tokens
SourceAnthropic pricing ↗OpenAI pricing ↗
GPT-5 mini lists the lower cost for this workload.

$325 vs $1,000 / month (100k calls, 5k in / 1k out)

Last updated
Methodology
Computed from list prices per 1M tokens; excludes prompt caching and batch discounts.
GPT-5 mini lists the larger context window.

400,000 tokens

Last updated
Harpd has not measured these two models head-to-head yet.

First benchmark: JSON extraction, 100 real tasks — target ship 2026-09-15

Last updated
Methodology
Until then, no performance win is claimed on this page — validate both models on your own tasks.
Claude Haiku 4.5

Capabilities

Claude Haiku 4.5 is positioned as a fast, cost-efficient model with strong performance for its tier, a 200k context window, and prompt caching.

Best for

High-volume tasks where small-tier output quality matters enough to pay roughly 4× GPT-5 mini's list price.

Limitations

$1/$5 per 1M is 4–2.5× GPT-5 mini's list price, and the 200k window is half of GPT-5 mini's.

GPT-5 mini

Capabilities

GPT-5 mini is a small, low-latency model with a 400k context window, prompt caching, and a very low per-token price aimed at high-volume calls.

Best for

Pure-volume classification, routing and extraction where unit cost and a 400k window matter most.

Limitations

Small reasoning models can drop below your quality bar on nuanced extraction — only a sampled evaluation on your tasks shows whether the 80% saving survives.

Recommendation

Both are designed for cheap, high-throughput work, so the pragmatic move is to benchmark each on your highest-volume path. Claude Haiku 4.5 tends to be chosen where output quality at the small tier matters; GPT-5 mini’s lower price suits pure volume. Neither is universally “better” — test both on your real traffic before standardizing.

Updated 2026-08-18. Sources: Anthropic and OpenAI official pricing pages (verified 2026-08-18); no Harpd-measured benchmark yet.

Methodology & sources

Prices on this page come from the Harpd pricing registry, which mirrors the officialAnthropic and OpenAI pricing pages and was last verified 2026-08-18. Capability notes summarize documented provider positioning — they are not Harpd measurements. Cheaper-cost claims are computed from the registry at a fixed reference workload, so they are reproducible from the published dataset. Read the pricing methodology and themodel replacement guide before switching a production workload.

Answer

Price tells you what a model costs. It does not tell you whether it can replace your current model on your real tasks.

Evidence

Claude Haiku 4.5 vs GPT-5 mini, answered

Which is cheaper, Claude Haiku 4.5 or GPT-5 mini?
GPT-5 mini lists the lower cost at Harpd's reference workload (100,000 calls/month, 5,000 input / 1,000 output tokens): about $325 versus $1,000 per month at list prices (0.25/2 vs 1/5 USD per 1M input/output tokens). The mix matters: if your workload is output-heavy, recompute with the model compare calculator.
What is the main difference between Claude Haiku 4.5 and GPT-5 mini?
GPT-5 mini lists the lower prices ($0.25/$2 per 1M versus $1/$5) and the larger context window (400k versus 200k); Claude Haiku 4.5 is positioned as the quality-stronger small tier at a higher list price.
Which has the larger context window?
GPT-5 mini lists 400,000 tokens versus 200,000 for Claude Haiku 4.5, according to the Harpd pricing registry (last verified 2026-08-18).
Which should I choose?
Both are designed for cheap, high-throughput work, so the pragmatic move is to benchmark each on your highest-volume path. Claude Haiku 4.5 tends to be chosen where output quality at the small tier matters; GPT-5 mini’s lower price suits pure volume. Neither is universally “better” — test both on your real traffic before standardizing.