GPT-4o mini vs Grok 4

OpenAI · US  |  xAI · US · Updated June 2026

Quick verdict

Pick GPT-4o mini for very low cost per token for its capability tier or strong coding for a small model (87.2% humaneval). Pick Grok 4 for 256k context with native tool use or real-time data via x integration. On a tight budget at scale, GPT-4o mini is the value pick.

GPT-4o mini (OpenAI) and Grok 4 (xAI) are two of the models people most often weigh against each other in 2026. GPT-4o mini is openAI's budget small multimodal model — cheap, fast text-and-vision intelligence that outscored peer small models like Gemini 1.5 Flash and Claude 3 Haiku on MMLU and HumanEval at launch. Grok 4 is xAI's 2M-context model with live data access and strong reasoning chops. 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-4o miniGrok 4
ProviderOpenAI (US) xAI (US)
ReleasedJuly 18, 2024 July 9, 2025
Context window128K (~192 pages) 256K (~384 pages)
Price (in/out)$0.15/$0.6 per 1M tokens $3/$15 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image text, image, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Very low cost per token for its capability tier

GPT-4o mini

A core design strength of GPT-4o mini.

Strong coding for a small model (87.2% HumanEval)

GPT-4o mini

A core design strength of GPT-4o mini.

Leading MMLU among peer small models (82%)

GPT-4o mini

A core design strength of GPT-4o mini.

256K context with native tool use

Grok 4

A core design strength of Grok 4.

Real-time data via X integration

Grok 4

A core design strength of Grok 4.

Strong academic reasoning

Grok 4

A core design strength of Grok 4.

Lowest cost at scale

GPT-4o mini

At $0.15/$0.6 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

Its 256K window is about 2× larger, fitting roughly 384 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

GPT-4o mini

At $0.15/$0.6 per 1M tokens it undercuts Grok 4, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Grok 4

Larger 256K window fits more in one prompt.

Anyone whose priority is very low cost per token for its capability tier

GPT-4o mini

It is specifically built for that.

Anyone whose priority is 256k context with native tool use

Grok 4

That is its strongest area.

GPT-4o mini: where it fits

OpenAI's budget small multimodal model — cheap, fast text-and-vision intelligence that outscored peer small models like Gemini 1.5 Flash and Claude 3 Haiku on MMLU and HumanEval at launch. Released July 18, 2024 by OpenAI, it is built for very low cost per token for its capability tier, strong coding for a small model (87.2% HumanEval), leading MMLU among peer small models (82%), and text and image (vision) understanding in the API.

Its trade-offs are real: only 128K context with an October 2023 knowledge cutoff, and weaker on hard reasoning and coding than frontier models. At $0.15 in / $0.6 out per million tokens, it sits in the budget price band.

Grok 4: where it fits

XAI's 2M-context model with live data access and strong reasoning chops. Released July 9, 2025 by xAI, it is built for 256K context with native tool use, real-time data via X integration, strong academic reasoning, and no long-context surcharge.

Its trade-offs: smaller ecosystem than OpenAI/Google, and less independent benchmark coverage. At $3 in / $15 out per million tokens, it sits in the mid price band.

The bottom line for this matchup

GPT-4o mini and Grok 4 overlap enough that the right pick depends on your specific job. GPT-4o mini costs less per token; Grok 4 holds the larger context; and each leads in its own area — GPT-4o mini for very low cost per token for its capability tier, Grok 4 for 256k context with native tool use. Rather than crowning one, run the same hard task through both once and let the results decide.

Want both GPT-4o mini and Grok 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 GPT-4o mini or Grok 4 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-4o mini leans toward very low cost per token for its capability tier while Grok 4 leans toward 256k context with native tool use, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, GPT-4o mini or Grok 4?

GPT-4o mini is cheaper — $0.15/$0.6 per 1M tokens vs $3/$15 per 1M tokens, roughly 20× apart on input.

Which has the bigger context window?

Grok 4 — 256K vs 128K, about 2× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both GPT-4o mini and Grok 4 together?

Yes — a multi-model platform like LumiChats gives you GPT-4o mini, Grok 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, GPT-4o mini or Grok 4?

Grok 4 — released July 9, 2025, about 12 months after GPT-4o 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.