GPT-5.4 vs Grok 4.3

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 4.3 for video understanding from native video input or generating pdf, pptx, and xlsx files directly. On a tight budget at scale, Grok 4.3 is the value pick.

GPT-5.4 (OpenAI) and Grok 4.3 (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 4.3 is the current xAI flagship: 1M context, native video input, file generation, and live X data, ahead of the still-unreleased Grok 5. Their biggest split is price, and the breakdown below shows exactly how that plays out for your workload.

Key differences at a glance

Side-by-side specs

SpecGPT-5.4Grok 4.3
ProviderOpenAI (US) xAI (US)
ReleasedMarch 5, 2026 April 30, 2026
Context window1M (~1,500 pages) 1M (~1,500 pages)
Price (in/out)$2.5/$15 per 1M tokens $1.25/$2.5 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image, code text, image, video, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Strong general-purpose default

GPT-5.4

A core design strength of GPT-5.4.

Coding and software engineering

GPT-5.4

A core design strength of GPT-5.4.

Document understanding and tool use

GPT-5.4

A core design strength of GPT-5.4.

Video understanding from native video input

Grok 4.3

A core design strength of Grok 4.3.

Generating PDF, PPTX, and XLSX files directly

Grok 4.3

A core design strength of Grok 4.3.

Real-time questions using live X data

Grok 4.3

A core design strength of Grok 4.3.

Lowest cost at scale

Grok 4.3

At $1.25/$2.5 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Which should you pick?

A cost-sensitive startup shipping high volume

Grok 4.3

At $1.25/$2.5 per 1M tokens it undercuts GPT-5.4, and on millions of tokens that margin decides the monthly bill.

Anyone whose priority is strong general-purpose default

GPT-5.4

It is specifically built for that.

Anyone whose priority is video understanding from native video input

Grok 4.3

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 4.3: where it fits

The current xAI flagship: 1M context, native video input, file generation, and live X data, ahead of the still-unreleased Grok 5. Released April 30, 2026 by xAI, it is built for video understanding from native video input, generating PDF, PPTX, and XLSX files directly, real-time questions using live X data, and long-context, multi-agent reasoning.

Its trade-offs: higher context pricing on requests above 200K tokens, and less independent benchmark coverage than OpenAI, Anthropic, or Google. At $1.25 in / $2.5 out per million tokens, it sits in the mid price band.

The bottom line for this matchup

GPT-5.4 and Grok 4.3 overlap enough that the right pick depends on your specific job. Grok 4.3 costs less per token; and each leads in its own area — GPT-5.4 for strong general-purpose default, Grok 4.3 for video understanding from native video input. Rather than crowning one, run the same hard task through both once and let the results decide.

Want both GPT-5.4 and Grok 4.3 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 4.3 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 4.3 leans toward video understanding from native video input, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, GPT-5.4 or Grok 4.3?

Grok 4.3 is cheaper — $2.5/$15 per 1M tokens vs $1.25/$2.5 per 1M tokens, roughly 2× apart on input.

Which has the bigger context window?

Both advertise 1M (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.

Can I use both GPT-5.4 and Grok 4.3 together?

Yes — a multi-model platform like LumiChats gives you GPT-5.4, Grok 4.3 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 4.3?

Grok 4.3 — released April 30, 2026, about 56 days after GPT-5.4.

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.