Claude Sonnet 4.6 vs GPT-5.2

Anthropic · US  |  OpenAI · US · Updated June 2026

Quick verdict

Pick Claude Sonnet 4.6 for best value in the claude family or everyday professional work. Pick GPT-5.2 for strong all-round reasoning or reliable structured output. On a tight budget at scale, GPT-5.2 is the value pick.

Claude Sonnet 4.6 (Anthropic) and GPT-5.2 (OpenAI) are two of the models people most often weigh against each other in 2026. Claude Sonnet 4.6 is opus-class quality on most tasks at roughly 60% lower cost — the default workhorse. GPT-5.2 is a capable GPT-5-generation all-rounder, now succeeded by GPT-5.5. 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 Sonnet 4.6GPT-5.2
ProviderAnthropic (US) OpenAI (US)
ReleasedFebruary 2026 2026
Context window1M (~1,500 pages) 400K (~600 pages)
Price (in/out)$3/$15 per 1M tokens $1.5/$10 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image, code text, image, code
SWE-Bench Verified80% Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Best value in the Claude family

Claude Sonnet 4.6

A core design strength of Claude Sonnet 4.6.

Everyday professional work

Claude Sonnet 4.6

A core design strength of Claude Sonnet 4.6.

Long-document analysis

Claude Sonnet 4.6

A core design strength of Claude Sonnet 4.6.

Strong all-round reasoning

GPT-5.2

A core design strength of GPT-5.2.

Reliable structured output

GPT-5.2

A core design strength of GPT-5.2.

Broad ecosystem and tooling

GPT-5.2

A core design strength of GPT-5.2.

Lowest cost at scale

GPT-5.2

At $1.5/$10 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

Claude Sonnet 4.6

Its 1M window is about 2.5× larger, fitting roughly 1,500 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

GPT-5.2

At $1.5/$10 per 1M tokens it undercuts Claude Sonnet 4.6, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Claude Sonnet 4.6

Larger 1M window fits more in one prompt.

Anyone whose priority is best value in the claude family

Claude Sonnet 4.6

It is specifically built for that.

Anyone whose priority is strong all-round reasoning

GPT-5.2

That is its strongest area.

Claude Sonnet 4.6: where it fits

Opus-class quality on most tasks at roughly 60% lower cost — the default workhorse. Released February 2026 by Anthropic, it is built for best value in the Claude family, everyday professional work, long-document analysis, and coding at lower cost than Opus.

Its trade-offs are real: trails Opus on the hardest agentic tasks, and not an open-weight option. At $3 in / $15 out per million tokens, it sits in the mid price band.

GPT-5.2: where it fits

A capable GPT-5-generation all-rounder, now succeeded by GPT-5.5. Released 2026 by OpenAI, it is built for strong all-round reasoning, reliable structured output, broad ecosystem and tooling, and professional workflows.

Its trade-offs: superseded by GPT-5.5, and smaller context than flagships. At $1.5 in / $10 out per million tokens, it sits in the mid price band.

The bottom line for this matchup

Claude Sonnet 4.6 and GPT-5.2 overlap enough that the right pick depends on your specific job. GPT-5.2 costs less per token; Claude Sonnet 4.6 holds the larger context; and each leads in its own area — Claude Sonnet 4.6 for best value in the claude family, GPT-5.2 for strong all-round reasoning. Rather than crowning one, run the same hard task through both once and let the results decide.

Want both Claude Sonnet 4.6 and GPT-5.2 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 Sonnet 4.6 or GPT-5.2 better for coding?

Public SWE-Bench figures are not available for GPT-5.2, so the honest test is your own repository — run an identical real bug through both. By design, Claude Sonnet 4.6 leans toward best value in the claude family while GPT-5.2 leans toward strong all-round reasoning, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Claude Sonnet 4.6 or GPT-5.2?

GPT-5.2 is cheaper — $3/$15 per 1M tokens vs $1.5/$10 per 1M tokens, roughly 2× apart on input.

Which has the bigger context window?

Claude Sonnet 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 Sonnet 4.6 and GPT-5.2 together?

Yes — a multi-model platform like LumiChats gives you Claude Sonnet 4.6, GPT-5.2 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 Sonnet 4.6 or GPT-5.2?

Claude Sonnet 4.6 — released February 2026, about 34 days after GPT-5.2.

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.