GPT-6 Sol vs Grok 4.3

OpenAI · US  |  xAI · US · Updated June 2026

Quick verdict

Pick GPT-6 Sol for openai's everyday-work tier below gpt-6 astra, built with the same methods that improved astra's professional work, factuality, coding, computer use, and alignment or openai says it makes about half as many mistakes as gpt-5.6 sol. 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-6 Sol (OpenAI) and Grok 4.3 (xAI) are two of the models people most often weigh against each other in 2026. GPT-6 Sol is openAI's September 22, 2026 mid-tier update — Astra-derived improvements at half the GPT-5.6 Sol price, $2/$10 per million tokens. 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. 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-6 SolGrok 4.3
ProviderOpenAI (US) xAI (US)
ReleasedSeptember 22, 2026 April 30, 2026
Context window1.05M tokens (~1,575 pages) 1M (~1,500 pages)
Price (in/out)$2/$10 per 1M tokens $1.25/$2.5 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image text, image, video, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

OpenAI's everyday-work tier below GPT-6 Astra, built with the same methods that improved Astra's professional work, factuality, coding, computer use, and alignment

GPT-6 Sol

Grok 4.3 is comparatively weak here — less independent benchmark coverage than OpenAI, Anthropic, or Google

OpenAI says it makes about half as many mistakes as GPT-5.6 Sol

GPT-6 Sol

OpenAI's September 22, 2026 mid-tier update — Astra-derived improvements at half the GPT-5.6 Sol price, $2/$10 per million tokens — and it is the newer of the two.

Priced at half of the GPT-5.6 Sol/Luna generation's rates ($2/$10 vs GPT-5.6 Sol's $5/$30)

GPT-6 Sol

GPT-6 Sol lists priced at half of the GPT-5.6 Sol/Luna generation's rates ($2/$10 vs GPT-5.6 Sol's $5/$30) among its strengths; Grok 4.3 does not.

Video understanding from native video input

Grok 4.3

The current xAI flagship: 1M context, native video input, file generation, and live X data, ahead of the still-unreleased Grok 5 — and it runs cheaper at $1.25/$2.5 per 1M tokens.

Generating PDF, PPTX, and XLSX files directly

Grok 4.3

Grok 4.3 lists generating PDF, PPTX, and XLSX files directly among its strengths; GPT-6 Sol does not.

Real-time questions using live X data

Grok 4.3

Grok 4.3 lists real-time questions using live X data among its strengths; GPT-6 Sol does not.

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-6 Sol, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

GPT-6 Sol

Larger 1.05M tokens window fits more in one prompt.

Anyone whose priority is openai's everyday-work tier below gpt-6 astra, built with the same methods that improved astra's professional work, factuality, coding, computer use, and alignment

GPT-6 Sol

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-6 Sol: where it fits

OpenAI's September 22, 2026 mid-tier update — Astra-derived improvements at half the GPT-5.6 Sol price, $2/$10 per million tokens. Released September 22, 2026 by OpenAI, it is built for openAI's everyday-work tier below GPT-6 Astra, built with the same methods that improved Astra's professional work, factuality, coding, computer use, and alignment, openAI says it makes about half as many mistakes as GPT-5.6 Sol, priced at half of the GPT-5.6 Sol/Luna generation's rates ($2/$10 vs GPT-5.6 Sol's $5/$30), and 1.05M-token context window, input capped at 922K.

Its trade-offs are real: more reasoning capability than sibling GPT-6 Luna, but still positioned below flagship GPT-6 Astra, and cache-read pricing ($0.20/MTok) still costlier than Luna's ($0.01/MTok) for high-cache workloads. At $2 in / $10 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-6 Sol and Grok 4.3 overlap enough that the right pick depends on your specific job. Grok 4.3 costs less per token; GPT-6 Sol holds the larger context; and each leads in its own area — GPT-6 Sol for openai's everyday-work tier below gpt-6 astra, built with the same methods that improved astra's professional work, factuality, coding, computer use, and alignment, 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-6 Sol 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-6 Sol 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-6 Sol leans toward openai's everyday-work tier below gpt-6 astra, built with the same methods that improved astra's professional work, factuality, coding, computer use, and alignment 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-6 Sol or Grok 4.3?

Grok 4.3 is cheaper — $2/$10 per 1M tokens vs $1.25/$2.5 per 1M tokens, roughly 1.6× apart on input.

Which has the bigger context window?

Effectively neither — 1.05M tokens vs 1M is a difference of a few percent. Remember advertised ≠ usable: recall typically degrades before the ceiling.

Can I use both GPT-6 Sol and Grok 4.3 together?

Yes — a multi-model platform like LumiChats gives you GPT-6 Sol, 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-6 Sol or Grok 4.3?

GPT-6 Sol — released September 22, 2026, about 5 months after Grok 4.3.

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.