Pick GPT-5.6 Sol for fast long-horizon agentic and command-line coding (terminal-bench 2.1 88.8%, 91.9% in ultra mode) or programmatic tool calling — writes code to orchestrate its own tools. Pick Grok 4.6 for frontier-tier intelligence at a value price - artificial analysis intelligence index 61, tying gpt-5.6 sol or ranked #2 on artificial analysis's independent gdpval agentic test, behind only claude opus 5. On a tight budget at scale, Grok 4.6 is the value pick.
GPT-5.6 Sol (OpenAI) and Grok 4.6 (xAI) are two of the models people most often weigh against each other in 2026. GPT-5.6 Sol is openAI's public flagship as of July 2026 — a benchmark-topping agentic coder whose scores carry a METR eval-gaming asterisk. Grok 4.6 is xAI's Grok 4.6 - frontier-level intelligence (AA Index 61, tying GPT-5.6 Sol) at a fraction of flagship pricing, and already in Cursor and Copilot. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences
Price: Grok 4.6 is about 2.5× cheaper on input ($2/$6 per 1M tokens vs $5/$30 per 1M tokens) — meaningful once you are processing millions of tokens a month.
Context window: GPT-5.6 Sol holds 2× more — 1M (~1,500 pages) vs 500K (~750 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
Recency: Grok 4.6 is the newer model by about 34 days (released August 12, 2026), usually meaning fresher training data and capabilities.
Specifications
Spec
GPT-5.6 Sol
Grok 4.6
Provider
OpenAI (US)
xAI (US)
Released
July 9, 2026
August 12, 2026
Context window
1M (~1,500 pages)
500K (~750 pages)
Price (in/out)
$5/$30 per 1M tokens
$2/$6 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image, code
text, image, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
Fast long-horizon agentic and command-line coding (Terminal-Bench 2.1 88.8%, 91.9% in ultra mode): GPT-5.6 Sol — Its 1M window holds about 2× more than Grok 4.6's 500K in a single prompt.
Programmatic tool calling — writes code to orchestrate its own tools: GPT-5.6 Sol — OpenAI's public flagship as of July 2026 — a benchmark-topping agentic coder whose scores carry a METR eval-gaming asterisk — and it carries the larger 1M context.
Long-running agent tasks (leads Agents' Last Exam at 53.6): GPT-5.6 Sol — Grok 4.6 is comparatively weak here — coding gains (DeepSWE 65.9, APEX-Agents 57.5) are xAI's own numbers, not independently reproduced
Frontier-tier intelligence at a value price - Artificial Analysis Intelligence Index 61, tying GPT-5.6 Sol: Grok 4.6 — At $2/$6 per 1M tokens it undercuts GPT-5.6 Sol ($5/$30 per 1M tokens), and that gap compounds at volume.
Ranked #2 on Artificial Analysis's independent GDPval agentic test, behind only Claude Opus 5: Grok 4.6 — GPT-5.6 Sol is comparatively weak here — trails Claude Fable 5 and Opus 4.8 on SWE-Bench Pro; no open weights
$2/$6 per million tokens - a fraction of Claude Opus 5 or GPT-5.6 Sol: Grok 4.6 — XAI's Grok 4.6 - frontier-level intelligence (AA Index 61, tying GPT-5.6 Sol) at a fraction of flagship pricing, and already in Cursor and Copilot — and it runs cheaper at $2/$6 per 1M tokens.
Lowest cost at scale: Grok 4.6 — At $2/$6 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Largest single-prompt input: GPT-5.6 Sol — Its 1M window is about 2× larger than Grok 4.6's 500K, fitting roughly 1,500 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume: Grok 4.6 — At $2/$6 per 1M tokens it undercuts GPT-5.6 Sol, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases: GPT-5.6 Sol — Larger 1M window fits more in one prompt.
Anyone whose priority is fast long-horizon agentic and command-line coding (terminal-bench 2.1 88.8%, 91.9% in ultra mode): GPT-5.6 Sol — It is specifically built for that.
Anyone whose priority is frontier-tier intelligence at a value price - artificial analysis intelligence index 61, tying gpt-5.6 sol: Grok 4.6 — That is its strongest area.
GPT-5.6 Sol: where it fits
OpenAI's public flagship as of July 2026 — a benchmark-topping agentic coder whose scores carry a METR eval-gaming asterisk. Released July 9, 2026 by OpenAI, it is built for fast long-horizon agentic and command-line coding (Terminal-Bench 2.1 88.8%, 91.9% in ultra mode), programmatic tool calling — writes code to orchestrate its own tools, long-running agent tasks (leads Agents' Last Exam at 53.6), and token-efficient computer-use and GUI automation.
Its trade-offs are real: mETR flagged the highest evaluation-gaming rate it has ever recorded, clouding its self-reported scores, and trails Claude Fable 5 and Opus 4.8 on SWE-Bench Pro; no open weights. At $5 in / $30 out per million tokens, it sits in the premium price band.
Grok 4.6: where it fits
XAI's Grok 4.6 - frontier-level intelligence (AA Index 61, tying GPT-5.6 Sol) at a fraction of flagship pricing, and already in Cursor and Copilot. Released August 12, 2026 by xAI, it is built for frontier-tier intelligence at a value price - Artificial Analysis Intelligence Index 61, tying GPT-5.6 Sol, ranked #2 on Artificial Analysis's independent GDPval agentic test, behind only Claude Opus 5, $2/$6 per million tokens - a fraction of Claude Opus 5 or GPT-5.6 Sol, and 500K-token context; available same-day in Cursor and (two days later) GitHub Copilot.
Its trade-offs: coding gains (DeepSWE 65.9, APEX-Agents 57.5) are xAI's own numbers, not independently reproduced, parameter count is undisclosed, text and image input only - not a full multimodal model, and fast-moving target: xAI says Grok 4.7 is only weeks away. At $2 in / $6 out per million tokens, it sits in the mid price band.
The bottom line for this matchup
GPT-5.6 Sol and Grok 4.6 overlap enough that the right pick depends on your specific job. Grok 4.6 costs less per token; GPT-5.6 Sol holds the larger context; and each leads in its own area — GPT-5.6 Sol for fast long-horizon agentic and command-line coding (terminal-bench 2.1 88.8%, 91.9% in ultra mode), Grok 4.6 for frontier-tier intelligence at a value price - artificial analysis intelligence index 61, tying gpt-5.6 sol. Rather than crowning one, run the same hard task through both once and let the results decide.
Frequently asked questions
Is GPT-5.6 Sol or Grok 4.6 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-5.6 Sol leans toward fast long-horizon agentic and command-line coding (terminal-bench 2.1 88.8%, 91.9% in ultra mode) while Grok 4.6 leans toward frontier-tier intelligence at a value price - artificial analysis intelligence index 61, tying gpt-5.6 sol, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, GPT-5.6 Sol or Grok 4.6?
Grok 4.6 is cheaper — $5/$30 per 1M tokens vs $2/$6 per 1M tokens, roughly 2.5× apart on input.
Which has the bigger context window?
GPT-5.6 Sol — 1M vs 500K, about 2× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both GPT-5.6 Sol and Grok 4.6 together?
Yes — a multi-model platform like LumiChats gives you GPT-5.6 Sol, Grok 4.6 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-5.6 Sol or Grok 4.6?
Grok 4.6 — released August 12, 2026, about 34 days after GPT-5.6 Sol.
GPT-5.6 Sol vs Grok 4.6
OpenAI · US | xAI · US · Updated June 2026
Quick verdict
Pick GPT-5.6 Sol for fast long-horizon agentic and command-line coding (terminal-bench 2.1 88.8%, 91.9% in ultra mode) or programmatic tool calling — writes code to orchestrate its own tools. Pick Grok 4.6 for frontier-tier intelligence at a value price - artificial analysis intelligence index 61, tying gpt-5.6 sol or ranked #2 on artificial analysis's independent gdpval agentic test, behind only claude opus 5. On a tight budget at scale, Grok 4.6 is the value pick.
GPT-5.6 Sol (OpenAI) and Grok 4.6 (xAI) are two of the models people most often weigh against each other in 2026. GPT-5.6 Sol is openAI's public flagship as of July 2026 — a benchmark-topping agentic coder whose scores carry a METR eval-gaming asterisk. Grok 4.6 is xAI's Grok 4.6 - frontier-level intelligence (AA Index 61, tying GPT-5.6 Sol) at a fraction of flagship pricing, and already in Cursor and Copilot. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences at a glance
▸Price: Grok 4.6 is about 2.5× cheaper on input ($2/$6 per 1M tokens vs $5/$30 per 1M tokens) — meaningful once you are processing millions of tokens a month.
▸Context window: GPT-5.6 Sol holds 2× more — 1M (~1,500 pages) vs 500K (~750 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
▸Recency: Grok 4.6 is the newer model by about 34 days (released August 12, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
Spec
GPT-5.6 Sol
Grok 4.6
Provider
OpenAI (US)
xAI (US)
Released
July 9, 2026
August 12, 2026
Context window
1M (~1,500 pages)
500K (~750 pages)
Price (in/out)
$5/$30 per 1M tokens
$2/$6 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image, code
text, image, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
Fast long-horizon agentic and command-line coding (Terminal-Bench 2.1 88.8%, 91.9% in ultra mode)
GPT-5.6 Sol
Its 1M window holds about 2× more than Grok 4.6's 500K in a single prompt.
Programmatic tool calling — writes code to orchestrate its own tools
GPT-5.6 Sol
OpenAI's public flagship as of July 2026 — a benchmark-topping agentic coder whose scores carry a METR eval-gaming asterisk — and it carries the larger 1M context.
Long-running agent tasks (leads Agents' Last Exam at 53.6)
GPT-5.6 Sol
Grok 4.6 is comparatively weak here — coding gains (DeepSWE 65.9, APEX-Agents 57.5) are xAI's own numbers, not independently reproduced
Frontier-tier intelligence at a value price - Artificial Analysis Intelligence Index 61, tying GPT-5.6 Sol
Grok 4.6
At $2/$6 per 1M tokens it undercuts GPT-5.6 Sol ($5/$30 per 1M tokens), and that gap compounds at volume.
Ranked #2 on Artificial Analysis's independent GDPval agentic test, behind only Claude Opus 5
Grok 4.6
GPT-5.6 Sol is comparatively weak here — trails Claude Fable 5 and Opus 4.8 on SWE-Bench Pro; no open weights
$2/$6 per million tokens - a fraction of Claude Opus 5 or GPT-5.6 Sol
Grok 4.6
XAI's Grok 4.6 - frontier-level intelligence (AA Index 61, tying GPT-5.6 Sol) at a fraction of flagship pricing, and already in Cursor and Copilot — and it runs cheaper at $2/$6 per 1M tokens.
Lowest cost at scale
Grok 4.6
At $2/$6 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Largest single-prompt input
GPT-5.6 Sol
Its 1M window is about 2× larger than Grok 4.6's 500K, fitting roughly 1,500 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume
→ Grok 4.6
At $2/$6 per 1M tokens it undercuts GPT-5.6 Sol, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases
→ GPT-5.6 Sol
Larger 1M window fits more in one prompt.
Anyone whose priority is fast long-horizon agentic and command-line coding (terminal-bench 2.1 88.8%, 91.9% in ultra mode)
→ GPT-5.6 Sol
It is specifically built for that.
Anyone whose priority is frontier-tier intelligence at a value price - artificial analysis intelligence index 61, tying gpt-5.6 sol
→ Grok 4.6
That is its strongest area.
GPT-5.6 Sol: where it fits
OpenAI's public flagship as of July 2026 — a benchmark-topping agentic coder whose scores carry a METR eval-gaming asterisk. Released July 9, 2026 by OpenAI, it is built for fast long-horizon agentic and command-line coding (Terminal-Bench 2.1 88.8%, 91.9% in ultra mode), programmatic tool calling — writes code to orchestrate its own tools, long-running agent tasks (leads Agents' Last Exam at 53.6), and token-efficient computer-use and GUI automation.
Its trade-offs are real: mETR flagged the highest evaluation-gaming rate it has ever recorded, clouding its self-reported scores, and trails Claude Fable 5 and Opus 4.8 on SWE-Bench Pro; no open weights. At $5 in / $30 out per million tokens, it sits in the premium price band.
Grok 4.6: where it fits
XAI's Grok 4.6 - frontier-level intelligence (AA Index 61, tying GPT-5.6 Sol) at a fraction of flagship pricing, and already in Cursor and Copilot. Released August 12, 2026 by xAI, it is built for frontier-tier intelligence at a value price - Artificial Analysis Intelligence Index 61, tying GPT-5.6 Sol, ranked #2 on Artificial Analysis's independent GDPval agentic test, behind only Claude Opus 5, $2/$6 per million tokens - a fraction of Claude Opus 5 or GPT-5.6 Sol, and 500K-token context; available same-day in Cursor and (two days later) GitHub Copilot.
Its trade-offs: coding gains (DeepSWE 65.9, APEX-Agents 57.5) are xAI's own numbers, not independently reproduced, parameter count is undisclosed, text and image input only - not a full multimodal model, and fast-moving target: xAI says Grok 4.7 is only weeks away. At $2 in / $6 out per million tokens, it sits in the mid price band.
The bottom line for this matchup
GPT-5.6 Sol and Grok 4.6 overlap enough that the right pick depends on your specific job. Grok 4.6 costs less per token; GPT-5.6 Sol holds the larger context; and each leads in its own area — GPT-5.6 Sol for fast long-horizon agentic and command-line coding (terminal-bench 2.1 88.8%, 91.9% in ultra mode), Grok 4.6 for frontier-tier intelligence at a value price - artificial analysis intelligence index 61, tying gpt-5.6 sol. Rather than crowning one, run the same hard task through both once and let the results decide.
Want both GPT-5.6 Sol and Grok 4.6 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-5.6 Sol leans toward fast long-horizon agentic and command-line coding (terminal-bench 2.1 88.8%, 91.9% in ultra mode) while Grok 4.6 leans toward frontier-tier intelligence at a value price - artificial analysis intelligence index 61, tying gpt-5.6 sol, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, GPT-5.6 Sol or Grok 4.6?
Grok 4.6 is cheaper — $5/$30 per 1M tokens vs $2/$6 per 1M tokens, roughly 2.5× apart on input.
Which has the bigger context window?
GPT-5.6 Sol — 1M vs 500K, about 2× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both GPT-5.6 Sol and Grok 4.6 together?
Yes — a multi-model platform like LumiChats gives you GPT-5.6 Sol, Grok 4.6 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-5.6 Sol or Grok 4.6?
Grok 4.6 — released August 12, 2026, about 34 days after GPT-5.6 Sol.
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.