GPT-5.4 Mini vs Grok 4.5

OpenAI · US  |  xAI · US · Updated June 2026

Quick verdict

Pick GPT-5.4 Mini for free for every chatgpt user or fast, low-cost general tasks. Pick Grok 4.5 for cheap, token-efficient agentic coding — about gpt-5.5-codex quality at roughly half the cost or extreme token efficiency — around 4x fewer output tokens per task than opus 4.8. On a tight budget at scale, GPT-5.4 Mini is the value pick.

GPT-5.4 Mini (OpenAI) and Grok 4.5 (xAI) are two of the models people most often weigh against each other in 2026. GPT-5.4 Mini is openAI's free, fast workhorse — capable general AI with no subscription needed. Grok 4.5 is xAI's first coding-focused model — pitched as Opus-class but faster, more token-efficient, and cheaper, undercutting GPT-5.5-Codex. 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

SpecGPT-5.4 MiniGrok 4.5
ProviderOpenAI (US) xAI (US)
ReleasedMarch 17, 2026 July 8, 2026
Context window400K (~600 pages) 500K (~750 pages)
Price (in/out)$0.75/$4.5 per 1M tokens $2/$6 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

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.

Cheap, token-efficient agentic coding — about GPT-5.5-Codex quality at roughly half the cost

Grok 4.5

A core design strength of Grok 4.5.

Extreme token efficiency — around 4x fewer output tokens per task than Opus 4.8

Grok 4.5

A core design strength of Grok 4.5.

In-IDE coding, trained on real Cursor developer sessions and shipped natively in Cursor

Grok 4.5

A core design strength of Grok 4.5.

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

Grok 4.5

Its 500K window is about 1.3× larger, fitting roughly 750 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 Grok 4.5, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Grok 4.5

Larger 500K window fits more in one prompt.

Anyone whose priority is free for every chatgpt user

GPT-5.4 Mini

It is specifically built for that.

Anyone whose priority is cheap, token-efficient agentic coding — about gpt-5.5-codex quality at roughly half the cost

Grok 4.5

That is its strongest area.

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 are real: 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.

Grok 4.5: where it fits

XAI's first coding-focused model — pitched as Opus-class but faster, more token-efficient, and cheaper, undercutting GPT-5.5-Codex. Released July 8, 2026 by xAI, it is built for cheap, token-efficient agentic coding — about GPT-5.5-Codex quality at roughly half the cost, extreme token efficiency — around 4x fewer output tokens per task than Opus 4.8, in-IDE coding, trained on real Cursor developer sessions and shipped natively in Cursor, and top-tier placement on the Artificial Analysis Intelligence Index.

Its trade-offs: smaller 500K context (halved from the 1M generation), with pricing that doubles above 200K tokens, and eU launch delayed; no open weights. At $2 in / $6 out per million tokens, it sits in the mid price band.

The bottom line for this matchup

GPT-5.4 Mini and Grok 4.5 overlap enough that the right pick depends on your specific job. GPT-5.4 Mini costs less per token; Grok 4.5 holds the larger context; and each leads in its own area — GPT-5.4 Mini for free for every chatgpt user, Grok 4.5 for cheap, token-efficient agentic coding — about gpt-5.5-codex quality at roughly half the cost. Rather than crowning one, run the same hard task through both once and let the results decide.

Want both GPT-5.4 Mini and Grok 4.5 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 GPT-5.4 Mini or Grok 4.5 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, GPT-5.4 Mini leans toward free for every chatgpt user while Grok 4.5 leans toward cheap, token-efficient agentic coding — about gpt-5.5-codex quality at roughly half the cost, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, GPT-5.4 Mini or Grok 4.5?

GPT-5.4 Mini is cheaper — $0.75/$4.5 per 1M tokens vs $2/$6 per 1M tokens, roughly 2.7× apart on input.

Which has the bigger context window?

Grok 4.5 — 500K vs 400K, about 1.3× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both GPT-5.4 Mini and Grok 4.5 together?

Yes — a multi-model platform like LumiChats gives you GPT-5.4 Mini, Grok 4.5 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, GPT-5.4 Mini or Grok 4.5?

Grok 4.5 — released July 8, 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.