GPT-5.4 vs Grok 4

OpenAI · US  |  xAI · US · Updated June 2026

Quick verdict

Pick GPT-5.4 for strong general-purpose default or coding and software engineering. Pick Grok 4 for 256k context with native tool use or real-time data via x integration. On a tight budget at scale, GPT-5.4 is the value pick.

GPT-5.4 (OpenAI) and Grok 4 (xAI) are two of the models people most often weigh against each other in 2026. GPT-5.4 is openAI's 2026 workhorse — unifies Codex and GPT into a strong default that costs half of GPT-5.5. 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-5.4Grok 4
ProviderOpenAI (US) xAI (US)
ReleasedMarch 5, 2026 July 9, 2025
Context window1M (~1,500 pages) 256K (~384 pages)
Price (in/out)$2.5/$15 per 1M tokens $3/$15 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

Strong general-purpose default

GPT-5.4

OpenAI's 2026 workhorse — unifies Codex and GPT into a strong default that costs half of GPT-5.5 — and it runs cheaper at $2.5/$15 per 1M tokens.

Coding and software engineering

GPT-5.4

OpenAI's 2026 workhorse — unifies Codex and GPT into a strong default that costs half of GPT-5.5 — and it carries the larger 1M context.

Document understanding and tool use

GPT-5.4

Its 1M window holds about 3.9× more than Grok 4's 256K in a single prompt.

256K context with native tool use

Grok 4

Grok 4 lists 256K context with native tool use among its strengths; GPT-5.4 does not.

Real-time data via X integration

Grok 4

Grok 4 lists real-time data via X integration among its strengths; GPT-5.4 does not.

Strong academic reasoning

Grok 4

Grok 4 lists strong academic reasoning among its strengths; GPT-5.4 does not.

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.

Largest single-prompt input

GPT-5.4

Its 1M window is about 3.9× larger than Grok 4's 256K, fitting roughly 1,500 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

GPT-5.4

At $2.5/$15 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

GPT-5.4

Larger 1M window fits more in one prompt.

Anyone whose priority is strong general-purpose default

GPT-5.4

It is specifically built for that.

Anyone whose priority is 256k context with native tool use

Grok 4

That is its strongest area.

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 are real: 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.

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-5.4 and Grok 4 overlap enough that the right pick depends on your specific job. GPT-5.4 costs less per token; GPT-5.4 holds the larger context; and each leads in its own area — GPT-5.4 for strong general-purpose default, 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-5.4 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-5.4 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-5.4 leans toward strong general-purpose default 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-5.4 or Grok 4?

GPT-5.4 is cheaper — $2.5/$15 per 1M tokens vs $3/$15 per 1M tokens, roughly 1.2× apart on input.

Which has the bigger context window?

GPT-5.4 — 1M vs 256K, about 3.9× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both GPT-5.4 and Grok 4 together?

Yes — a multi-model platform like LumiChats gives you GPT-5.4, 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-5.4 or Grok 4?

GPT-5.4 — released March 5, 2026, about 8 months after Grok 4.

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.