Claude Sonnet 5 vs GPT-5.4 Mini

Anthropic · US  |  OpenAI · US · Updated June 2026

Quick verdict

Pick Claude Sonnet 5 for agentic workflows that plan, use tools, and run autonomously or multi-step coding, debugging, and tool use. Pick GPT-5.4 Mini for free for every chatgpt user or fast, low-cost general tasks. On a tight budget at scale, GPT-5.4 Mini is the value pick.

Claude Sonnet 5 (Anthropic) and GPT-5.4 Mini (OpenAI) are two of the models people most often weigh against each other in 2026. Claude Sonnet 5 is anthropic's most agentic Sonnet, with near-Opus-4.8 performance at Sonnet prices; the default model on Free and Pro. GPT-5.4 Mini is openAI's free, fast workhorse — capable general AI with no subscription needed. 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 5GPT-5.4 Mini
ProviderAnthropic (US) OpenAI (US)
ReleasedJune 30, 2026 March 17, 2026
Context window1M (~1,500 pages) 400K (~600 pages)
Price (in/out)$3/$15 per 1M tokens $0.75/$4.5 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image, code text, image, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Agentic workflows that plan, use tools, and run autonomously

Claude Sonnet 5

A core design strength of Claude Sonnet 5.

Multi-step coding, debugging, and tool use

Claude Sonnet 5

A core design strength of Claude Sonnet 5.

Everyday professional and knowledge work

Claude Sonnet 5

A core design strength of Claude Sonnet 5.

Free for every ChatGPT user

GPT-5.4 Mini

A core design strength of GPT-5.4 Mini.

Fast, low-cost general tasks

GPT-5.4 Mini

A core design strength of GPT-5.4 Mini.

Subagent capabilities

GPT-5.4 Mini

A core design strength of GPT-5.4 Mini.

Lowest cost at scale

GPT-5.4 Mini

At $0.75/$4.5 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 5

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-5.4 Mini

At $0.75/$4.5 per 1M tokens it undercuts Claude Sonnet 5, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Claude Sonnet 5

Larger 1M window fits more in one prompt.

Anyone whose priority is agentic workflows that plan, use tools, and run autonomously

Claude Sonnet 5

It is specifically built for that.

Anyone whose priority is free for every chatgpt user

GPT-5.4 Mini

That is its strongest area.

Claude Sonnet 5: where it fits

Anthropic's most agentic Sonnet, with near-Opus-4.8 performance at Sonnet prices; the default model on Free and Pro. Released June 30, 2026 by Anthropic, it is built for agentic workflows that plan, use tools, and run autonomously, multi-step coding, debugging, and tool use, everyday professional and knowledge work, and long-document analysis and reasoning.

Its trade-offs are real: lower peak accuracy than Opus 4.8 on the hardest tasks, and an updated tokenizer that can use 1.0-1.35x more tokens for the same text. At $3 in / $15 out per million tokens, it sits in the mid price band.

GPT-5.4 Mini: where it fits

OpenAI's free, fast workhorse — capable general AI with no subscription needed. Released March 17, 2026 by OpenAI, it is built for free for every ChatGPT user, fast, low-cost general tasks, subagent capabilities, and native multimodal reasoning.

Its trade-offs: smaller context than flagship models, and not for the hardest reasoning. At $0.75 in / $4.5 out per million tokens, it sits in the budget price band.

The bottom line for this matchup

Claude Sonnet 5 and GPT-5.4 Mini overlap enough that the right pick depends on your specific job. GPT-5.4 Mini costs less per token; Claude Sonnet 5 holds the larger context; and each leads in its own area — Claude Sonnet 5 for agentic workflows that plan, use tools, and run autonomously, GPT-5.4 Mini for free for every chatgpt user. Rather than crowning one, run the same hard task through both once and let the results decide.

Want both Claude Sonnet 5 and GPT-5.4 Mini 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 5 or GPT-5.4 Mini better for coding?

Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, Claude Sonnet 5 leans toward agentic workflows that plan, use tools, and run autonomously while GPT-5.4 Mini leans toward free for every chatgpt user, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Claude Sonnet 5 or GPT-5.4 Mini?

GPT-5.4 Mini is cheaper — $3/$15 per 1M tokens vs $0.75/$4.5 per 1M tokens, roughly 4× apart on input.

Which has the bigger context window?

Claude Sonnet 5 — 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 5 and GPT-5.4 Mini together?

Yes — a multi-model platform like LumiChats gives you Claude Sonnet 5, GPT-5.4 Mini 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 5 or GPT-5.4 Mini?

Claude Sonnet 5 — released June 30, 2026, about 4 months after GPT-5.4 Mini.

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.