Claude Opus 4.6 vs GPT-5.4 Nano

Anthropic · US  |  OpenAI · US · Updated June 2026

Quick verdict

Pick Claude Opus 4.6 for agentic coding and debugging in large codebases or long-running, multi-step autonomous agent tasks. 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 Opus 4.6 (Anthropic) and GPT-5.4 Nano (OpenAI) are two of the models people most often weigh against each other in 2026. Claude Opus 4.6 is anthropic's February 2026 flagship Opus and the first Opus-class model with a 1M-token context window, built for agentic coding and long-running professional tasks. 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 Opus 4.6GPT-5.4 Nano
ProviderAnthropic (US) OpenAI (US)
ReleasedFebruary 5, 2026 March 17, 2026
Context window1M (~1,500 pages) 400K (~600 pages)
Price (in/out)$5/$25 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 Verified80.8% Not published
MRCR v2 @ 1M76% Not published

Who wins what

Agentic coding and debugging in large codebases

Claude Opus 4.6

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

Long-running, multi-step autonomous agent tasks

Claude Opus 4.6

Its 1M window holds about 2.5× more than GPT-5.4 Nano's 400K in a single prompt.

Frontier multidisciplinary reasoning (leads Humanity's Last Exam)

Claude Opus 4.6

Anthropic's February 2026 flagship Opus and the first Opus-class model with a 1M-token context window, built for agentic coding and long-running professional tasks — and it carries the larger 1M context.

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 Opus 4.6 ($5/$25 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

Claude Opus 4.6 is comparatively weak here — top-tier per-token price, and its 1M-token context shipped as beta

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

Claude Opus 4.6

Its 1M window is about 2.5× larger than GPT-5.4 Nano's 400K, fitting roughly 1,500 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 Opus 4.6, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Claude Opus 4.6

Larger 1M window fits more in one prompt.

Anyone whose priority is agentic coding and debugging in large codebases

Claude Opus 4.6

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 Opus 4.6: where it fits

Anthropic's February 2026 flagship Opus and the first Opus-class model with a 1M-token context window, built for agentic coding and long-running professional tasks. Released February 5, 2026 by Anthropic, it is built for agentic coding and debugging in large codebases, long-running, multi-step autonomous agent tasks, frontier multidisciplinary reasoning (leads Humanity's Last Exam), and economically valuable knowledge work in finance and legal (GDPval-AA).

Its trade-offs are real: superseded by newer Claude Opus 4.7 and 4.8 (now a legacy model), and top-tier per-token price, and its 1M-token context shipped as beta. At $5 in / $25 out per million tokens, it sits in the premium 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 Opus 4.6 and GPT-5.4 Nano overlap enough that the right pick depends on your specific job. GPT-5.4 Nano costs less per token; Claude Opus 4.6 holds the larger context; and each leads in its own area — Claude Opus 4.6 for agentic coding and debugging in large codebases, 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 Opus 4.6 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 Opus 4.6 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 Opus 4.6 leans toward agentic coding and debugging in large codebases 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 Opus 4.6 or GPT-5.4 Nano?

GPT-5.4 Nano is cheaper — $5/$25 per 1M tokens vs $0.2/$1.25 per 1M tokens, roughly 25× apart on input.

Which has the bigger context window?

Claude Opus 4.6 — 1M vs 400K, about 2.5× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both Claude Opus 4.6 and GPT-5.4 Nano together?

Yes — a multi-model platform like LumiChats gives you Claude Opus 4.6, 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 Opus 4.6 or GPT-5.4 Nano?

GPT-5.4 Nano — released March 17, 2026, about 40 days after Claude Opus 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.