Claude Haiku 4.5 vs GPT-5.4 Nano

Anthropic · US  |  OpenAI · US · Updated June 2026

Quick verdict

Pick Claude Haiku 4.5 for fastest claude model or near-frontier coding for its tier — 73.3% on swe-bench verified. Pick GPT-5.4 Nano for cheapest gpt-5.4-family tier at $0.20/$1.25 — built for high-volume, latency-sensitive work or classification, extraction, ranking and sub-agent execution at scale. On a tight budget at scale, GPT-5.4 Nano is the value pick.

Claude Haiku 4.5 (Anthropic) and GPT-5.4 Nano (OpenAI) are two of the models people most often weigh against each other in 2026. Claude Haiku 4.5 is anthropic's fastest, most compact model — built for speed and volume. GPT-5.4 Nano is openAI's cheapest GPT-5.4 variant at $0.20/$1.25 with a 400K window — a speed-and-cost tier for high-volume tasks, not deep reasoning. They diverge most on price and context window — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecClaude Haiku 4.5GPT-5.4 Nano
ProviderAnthropic (US) OpenAI (US)
ReleasedOctober 15, 2025 March 17, 2026
Context window200K (~300 pages) 400K (~600 pages)
Price (in/out)$1/$5 per 1M tokens $0.2/$1.25 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image, code text, image, code
SWE-Bench Verified73.3% Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Fastest Claude model

Claude Haiku 4.5

Claude Haiku 4.5 lists fastest Claude model among its strengths; GPT-5.4 Nano does not.

Near-frontier coding for its tier — 73.3% on SWE-Bench Verified

Claude Haiku 4.5

GPT-5.4 Nano is comparatively weak here — a nano tier — not built for hard reasoning or frontier coding

Low-latency, high-volume API calls

Claude Haiku 4.5

Claude Haiku 4.5 lists low-latency, high-volume API calls among its strengths; GPT-5.4 Nano does not.

Cheapest GPT-5.4-family tier at $0.20/$1.25 — built for high-volume, latency-sensitive work

GPT-5.4 Nano

At $0.2/$1.25 per 1M tokens it undercuts Claude Haiku 4.5 ($1/$5 per 1M tokens), and that gap compounds at volume.

Classification, extraction, ranking and sub-agent execution at scale

GPT-5.4 Nano

OpenAI's cheapest GPT-5.4 variant at $0.20/$1.25 with a 400K window — a speed-and-cost tier for high-volume tasks, not deep reasoning — and it runs cheaper at $0.2/$1.25 per 1M tokens.

A 400K context in the smallest, fastest GPT-5.4 variant

GPT-5.4 Nano

Its 400K window holds about 2× more than Claude Haiku 4.5's 200K in a single prompt.

Lowest cost at scale

GPT-5.4 Nano

At $0.2/$1.25 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

GPT-5.4 Nano

Its 400K window is about 2× larger than Claude Haiku 4.5's 200K, fitting roughly 600 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

GPT-5.4 Nano

At $0.2/$1.25 per 1M tokens it undercuts Claude Haiku 4.5, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

GPT-5.4 Nano

Larger 400K window fits more in one prompt.

Anyone whose priority is fastest claude model

Claude Haiku 4.5

It is specifically built for that.

Anyone whose priority is cheapest gpt-5.4-family tier at $0.20/$1.25 — built for high-volume, latency-sensitive work

GPT-5.4 Nano

That is its strongest area.

Claude Haiku 4.5: where it fits

Anthropic's fastest, most compact model — built for speed and volume. Released October 15, 2025 by Anthropic, it is built for fastest Claude model, near-frontier coding for its tier — 73.3% on SWE-Bench Verified, low-latency, high-volume API calls, and cheapest Claude tier at $1/$5.

Its trade-offs are real: smallest context in the family (200K), and not for deep reasoning. At $1 in / $5 out per million tokens, it sits in the budget price band.

GPT-5.4 Nano: where it fits

OpenAI's cheapest GPT-5.4 variant at $0.20/$1.25 with a 400K window — a speed-and-cost tier for high-volume tasks, not deep reasoning. Released March 17, 2026 by OpenAI, it is built for cheapest GPT-5.4-family tier at $0.20/$1.25 — built for high-volume, latency-sensitive work, classification, extraction, ranking and sub-agent execution at scale, a 400K context in the smallest, fastest GPT-5.4 variant, and text and image input for cheap multimodal pipelines.

Its trade-offs: a nano tier — not built for hard reasoning or frontier coding, no published SWE-Bench Verified score (OpenAI reported SWE-Bench Pro instead), outclassed by GPT-5.4 and GPT-5.4 Mini whenever a task needs real depth, and image input only — no audio or video. At $0.2 in / $1.25 out per million tokens, it sits in the budget price band.

The bottom line for this matchup

Claude Haiku 4.5 and GPT-5.4 Nano overlap enough that the right pick depends on your specific job. GPT-5.4 Nano costs less per token; GPT-5.4 Nano holds the larger context; and each leads in its own area — Claude Haiku 4.5 for fastest claude model, GPT-5.4 Nano for cheapest gpt-5.4-family tier at $0.20/$1.25 — built for high-volume, latency-sensitive work. Rather than crowning one, run the same hard task through both once and let the results decide.

Want both Claude Haiku 4.5 and GPT-5.4 Nano without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.

See pricing

Frequently asked questions

Is Claude Haiku 4.5 or GPT-5.4 Nano better for coding?

Public SWE-Bench figures are not available for GPT-5.4 Nano, so the honest test is your own repository — run an identical real bug through both. By design, Claude Haiku 4.5 leans toward fastest claude model while GPT-5.4 Nano leans toward cheapest gpt-5.4-family tier at $0.20/$1.25 — built for high-volume, latency-sensitive work, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Claude Haiku 4.5 or GPT-5.4 Nano?

GPT-5.4 Nano is cheaper — $1/$5 per 1M tokens vs $0.2/$1.25 per 1M tokens, roughly 5× apart on input.

Which has the bigger context window?

GPT-5.4 Nano — 400K vs 200K, about 2× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both Claude Haiku 4.5 and GPT-5.4 Nano together?

Yes — a multi-model platform like LumiChats gives you Claude Haiku 4.5, GPT-5.4 Nano and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.

Which is newer, Claude Haiku 4.5 or GPT-5.4 Nano?

GPT-5.4 Nano — released March 17, 2026, about 5 months after Claude Haiku 4.5.

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.