Claude Opus 4.6 vs GPT-5.4

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 for strong general-purpose default or coding and software engineering. On a tight budget at scale, GPT-5.4 is the value pick.

Claude Opus 4.6 (Anthropic) and GPT-5.4 (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 is openAI's 2026 workhorse — unifies Codex and GPT into a strong default that costs half of GPT-5.5. Their biggest split is price, and the breakdown below shows exactly how that plays out for your workload.

Key differences at a glance

Side-by-side specs

SpecClaude Opus 4.6GPT-5.4
ProviderAnthropic (US) OpenAI (US)
ReleasedFebruary 5, 2026 March 5, 2026
Context window1M (~1,500 pages) 1M (~1,500 pages)
Price (in/out)$5/$25 per 1M tokens $2.5/$15 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

A core design strength of Claude Opus 4.6.

Long-running, multi-step autonomous agent tasks

Claude Opus 4.6

A core design strength of Claude Opus 4.6.

Frontier multidisciplinary reasoning (leads Humanity's Last Exam)

Claude Opus 4.6

A core design strength of Claude Opus 4.6.

Strong general-purpose default

GPT-5.4

A core design strength of GPT-5.4.

Coding and software engineering

GPT-5.4

A core design strength of GPT-5.4.

Document understanding and tool use

GPT-5.4

A core design strength of GPT-5.4.

Lowest cost at scale

GPT-5.4

At $2.5/$15 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Which should you pick?

A cost-sensitive startup shipping high volume

GPT-5.4

At $2.5/$15 per 1M tokens it undercuts Claude Opus 4.6, and on millions of tokens that margin decides the monthly bill.

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 strong general-purpose default

GPT-5.4

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: where it fits

OpenAI's 2026 workhorse — unifies Codex and GPT into a strong default that costs half of GPT-5.5. Released March 5, 2026 by OpenAI, it is built for strong general-purpose default, coding and software engineering, document understanding and tool use, and 1M context with good token efficiency.

Its trade-offs: topped by GPT-5.5 on the hardest tasks, and pricier than open-weight rivals. At $2.5 in / $15 out per million tokens, it sits in the mid price band.

The bottom line for this matchup

Claude Opus 4.6 and GPT-5.4 overlap enough that the right pick depends on your specific job. GPT-5.4 costs less per token; and each leads in its own area — Claude Opus 4.6 for agentic coding and debugging in large codebases, GPT-5.4 for strong general-purpose default. 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 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 better for coding?

Public SWE-Bench figures are not available for GPT-5.4, 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 leans toward strong general-purpose default, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Claude Opus 4.6 or GPT-5.4?

GPT-5.4 is cheaper — $5/$25 per 1M tokens vs $2.5/$15 per 1M tokens, roughly 2× apart on input.

Which has the bigger context window?

Both advertise 1M (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.

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

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

GPT-5.4 — released March 5, 2026, about 28 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.