Pick GPT-6 Astra for computer & browser use (screenspot-pro 92.7%) or cybersecurity exploit development (exploitbench 100%). Pick Grok 4 for 256k context with native tool use or real-time data via x integration. On a tight budget at scale, Grok 4 is the value pick.
GPT-6 Astra (OpenAI) and Grok 4 (xAI) are two of the models people most often weigh against each other in 2026. GPT-6 Astra is openAI's flagship reasoning model for computer use, browsing, coding and science, released September 3, 2026 with near-perfect scores on FrontierMath, ExploitBench and long-context recall benchmarks. 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
Price: Grok 4 is about 3.3× cheaper on input ($3/$15 per 1M tokens vs $10/$50 per 1M tokens) — meaningful once you are processing millions of tokens a month.
Context window: GPT-6 Astra holds 4.1× more — 1.05M tokens (~1,575 pages) vs 256K (~384 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
Recency: GPT-6 Astra is the newer model by about 14 months (released September 3, 2026), usually meaning fresher training data and capabilities.
Specifications
Spec
GPT-6 Astra
Grok 4
Provider
OpenAI (US)
xAI (US)
Released
September 3, 2026
July 9, 2025
Context window
1.05M tokens (~1,575 pages)
256K (~384 pages)
Price (in/out)
$10/$50 per 1M tokens
$3/$15 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image
text, image, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
96.3%
Not published
Who wins what
Computer & browser use (ScreenSpot-Pro 92.7%): GPT-6 Astra — OpenAI's flagship reasoning model for computer use, browsing, coding and science, released September 3, 2026 with near-perfect scores on FrontierMath, ExploitBench and long-context recall benchmarks — and it carries the larger 1.05M tokens context.
Cybersecurity exploit development (ExploitBench 100%): GPT-6 Astra — OpenAI's flagship reasoning model for computer use, browsing, coding and science, released September 3, 2026 with near-perfect scores on FrontierMath, ExploitBench and long-context recall benchmarks — and it is the newer of the two.
Frontier math reasoning (FrontierMath Tier 4: 97.6%): GPT-6 Astra — GPT-6 Astra lists frontier math reasoning (FrontierMath Tier 4: 97.6%) among its strengths; Grok 4 does not.
256K context with native tool use: Grok 4 — GPT-6 Astra is comparatively weak here — no native audio or video input
Real-time data via X integration: Grok 4 — XAI's 2M-context model with live data access and strong reasoning chops — and it runs cheaper at $3/$15 per 1M tokens.
Strong academic reasoning: Grok 4 — Grok 4 lists strong academic reasoning among its strengths; GPT-6 Astra does not.
Lowest cost at scale: Grok 4 — At $3/$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-6 Astra — Its 1.05M tokens window is about 4.1× larger than Grok 4's 256K, fitting roughly 1,575 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume: Grok 4 — At $3/$15 per 1M tokens it undercuts GPT-6 Astra, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases: GPT-6 Astra — Larger 1.05M tokens window fits more in one prompt.
Anyone whose priority is computer & browser use (screenspot-pro 92.7%): GPT-6 Astra — It is specifically built for that.
Anyone whose priority is 256k context with native tool use: Grok 4 — That is its strongest area.
GPT-6 Astra: where it fits
OpenAI's flagship reasoning model for computer use, browsing, coding and science, released September 3, 2026 with near-perfect scores on FrontierMath, ExploitBench and long-context recall benchmarks. Released September 3, 2026 by OpenAI, it is built for computer & browser use (ScreenSpot-Pro 92.7%), cybersecurity exploit development (ExploitBench 100%), frontier math reasoning (FrontierMath Tier 4: 97.6%), and long-context recall (MRCR v2 512K-1M: 96.3%).
Its trade-offs are real: no native audio or video input, pricing doubles for prompts over 272K tokens (input/cache 2x, output 1.5x), trails Meta's Muse Spark 1.3 on some coding evals (DeepSWE v1.1: 74.1 vs 75.4), and a separate opt-in "Daybreak" program gives vetted cybersecurity defenders a less-restricted version for legitimate vulnerability research; the public version already refuses ~91.5% of offensive cyber jailbreak attempts by default. At $10 in / $50 out per million tokens, it sits in the premium 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-6 Astra and Grok 4 overlap enough that the right pick depends on your specific job. Grok 4 costs less per token; GPT-6 Astra holds the larger context; and each leads in its own area — GPT-6 Astra for computer & browser use (screenspot-pro 92.7%), 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.
Frequently asked questions
Is GPT-6 Astra 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-6 Astra leans toward computer & browser use (screenspot-pro 92.7%) 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-6 Astra or Grok 4?
Grok 4 is cheaper — $10/$50 per 1M tokens vs $3/$15 per 1M tokens, roughly 3.3× apart on input.
Which has the bigger context window?
GPT-6 Astra — 1.05M tokens vs 256K, about 4.1× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both GPT-6 Astra and Grok 4 together?
Yes — a multi-model platform like LumiChats gives you GPT-6 Astra, 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-6 Astra or Grok 4?
GPT-6 Astra — released September 3, 2026, about 14 months after Grok 4.
GPT-6 Astra vs Grok 4
OpenAI · US | xAI · US · Updated June 2026
Quick verdict
Pick GPT-6 Astra for computer & browser use (screenspot-pro 92.7%) or cybersecurity exploit development (exploitbench 100%). Pick Grok 4 for 256k context with native tool use or real-time data via x integration. On a tight budget at scale, Grok 4 is the value pick.
GPT-6 Astra (OpenAI) and Grok 4 (xAI) are two of the models people most often weigh against each other in 2026. GPT-6 Astra is openAI's flagship reasoning model for computer use, browsing, coding and science, released September 3, 2026 with near-perfect scores on FrontierMath, ExploitBench and long-context recall benchmarks. 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
▸Price: Grok 4 is about 3.3× cheaper on input ($3/$15 per 1M tokens vs $10/$50 per 1M tokens) — meaningful once you are processing millions of tokens a month.
▸Context window: GPT-6 Astra holds 4.1× more — 1.05M tokens (~1,575 pages) vs 256K (~384 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
▸Recency: GPT-6 Astra is the newer model by about 14 months (released September 3, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
Spec
GPT-6 Astra
Grok 4
Provider
OpenAI (US)
xAI (US)
Released
September 3, 2026
July 9, 2025
Context window
1.05M tokens (~1,575 pages)
256K (~384 pages)
Price (in/out)
$10/$50 per 1M tokens
$3/$15 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image
text, image, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
96.3%
Not published
Who wins what
Computer & browser use (ScreenSpot-Pro 92.7%)
GPT-6 Astra
OpenAI's flagship reasoning model for computer use, browsing, coding and science, released September 3, 2026 with near-perfect scores on FrontierMath, ExploitBench and long-context recall benchmarks — and it carries the larger 1.05M tokens context.
Cybersecurity exploit development (ExploitBench 100%)
GPT-6 Astra
OpenAI's flagship reasoning model for computer use, browsing, coding and science, released September 3, 2026 with near-perfect scores on FrontierMath, ExploitBench and long-context recall benchmarks — and it is the newer of the two.
Frontier math reasoning (FrontierMath Tier 4: 97.6%)
GPT-6 Astra
GPT-6 Astra lists frontier math reasoning (FrontierMath Tier 4: 97.6%) among its strengths; Grok 4 does not.
256K context with native tool use
Grok 4
GPT-6 Astra is comparatively weak here — no native audio or video input
Real-time data via X integration
Grok 4
XAI's 2M-context model with live data access and strong reasoning chops — and it runs cheaper at $3/$15 per 1M tokens.
Strong academic reasoning
Grok 4
Grok 4 lists strong academic reasoning among its strengths; GPT-6 Astra does not.
Lowest cost at scale
Grok 4
At $3/$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-6 Astra
Its 1.05M tokens window is about 4.1× larger than Grok 4's 256K, fitting roughly 1,575 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume
→ Grok 4
At $3/$15 per 1M tokens it undercuts GPT-6 Astra, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases
→ GPT-6 Astra
Larger 1.05M tokens window fits more in one prompt.
Anyone whose priority is computer & browser use (screenspot-pro 92.7%)
→ GPT-6 Astra
It is specifically built for that.
Anyone whose priority is 256k context with native tool use
→ Grok 4
That is its strongest area.
GPT-6 Astra: where it fits
OpenAI's flagship reasoning model for computer use, browsing, coding and science, released September 3, 2026 with near-perfect scores on FrontierMath, ExploitBench and long-context recall benchmarks. Released September 3, 2026 by OpenAI, it is built for computer & browser use (ScreenSpot-Pro 92.7%), cybersecurity exploit development (ExploitBench 100%), frontier math reasoning (FrontierMath Tier 4: 97.6%), and long-context recall (MRCR v2 512K-1M: 96.3%).
Its trade-offs are real: no native audio or video input, pricing doubles for prompts over 272K tokens (input/cache 2x, output 1.5x), trails Meta's Muse Spark 1.3 on some coding evals (DeepSWE v1.1: 74.1 vs 75.4), and a separate opt-in "Daybreak" program gives vetted cybersecurity defenders a less-restricted version for legitimate vulnerability research; the public version already refuses ~91.5% of offensive cyber jailbreak attempts by default. At $10 in / $50 out per million tokens, it sits in the premium 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-6 Astra and Grok 4 overlap enough that the right pick depends on your specific job. Grok 4 costs less per token; GPT-6 Astra holds the larger context; and each leads in its own area — GPT-6 Astra for computer & browser use (screenspot-pro 92.7%), 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-6 Astra 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.
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 Astra leans toward computer & browser use (screenspot-pro 92.7%) 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-6 Astra or Grok 4?
Grok 4 is cheaper — $10/$50 per 1M tokens vs $3/$15 per 1M tokens, roughly 3.3× apart on input.
Which has the bigger context window?
GPT-6 Astra — 1.05M tokens vs 256K, about 4.1× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both GPT-6 Astra and Grok 4 together?
Yes — a multi-model platform like LumiChats gives you GPT-6 Astra, 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-6 Astra or Grok 4?
GPT-6 Astra — released September 3, 2026, about 14 months after Grok 4.
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.