Pick Claude Opus 4.6 for agentic coding and debugging in large codebases or long-running, multi-step autonomous agent tasks. 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.
Claude Opus 4.6 (Anthropic) and Grok 4 (xAI) are two of the models people most often weigh against each other in 2026. Claude Opus 4.6 is anthropic's February 2026 flagship Opus and the first Opus-class model with a 1M-token context window, built for agentic coding and long-running professional tasks. 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 1.7× cheaper on input ($3/$15 per 1M tokens vs $5/$25 per 1M tokens) — modest, but it adds up at steady volume.
Context window: Claude Opus 4.6 holds 3.9× more — 1M (~1,500 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: Claude Opus 4.6 is the newer model by about 7 months (released February 5, 2026), usually meaning fresher training data and capabilities.
Specifications
Spec
Claude Opus 4.6
Grok 4
Provider
Anthropic (US)
xAI (US)
Released
February 5, 2026
July 9, 2025
Context window
1M (~1,500 pages)
256K (~384 pages)
Price (in/out)
$5/$25 per 1M tokens
$3/$15 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image, code
text, image, code
SWE-Bench Verified
80.8%
Not published
MRCR v2 @ 1M
76%
Not published
Who wins what
Agentic coding and debugging in large codebases: Claude Opus 4.6 — A core design strength of Claude Opus 4.6.
Long-running, multi-step autonomous agent tasks: Claude Opus 4.6 — A core design strength of Claude Opus 4.6.
Frontier multidisciplinary reasoning (leads Humanity's Last Exam): Claude Opus 4.6 — A core design strength of Claude Opus 4.6.
256K context with native tool use: Grok 4 — A core design strength of Grok 4.
Real-time data via X integration: Grok 4 — A core design strength of Grok 4.
Strong academic reasoning: Grok 4 — A core design strength of Grok 4.
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: Claude Opus 4.6 — Its 1M window is about 3.9× larger, fitting roughly 1,500 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 Claude Opus 4.6, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases: Claude Opus 4.6 — Larger 1M window fits more in one prompt.
Anyone whose priority is agentic coding and debugging in large codebases: Claude Opus 4.6 — It is specifically built for that.
Anyone whose priority is 256k context with native tool use: Grok 4 — That is its strongest area.
Claude Opus 4.6: where it fits
Anthropic's February 2026 flagship Opus and the first Opus-class model with a 1M-token context window, built for agentic coding and long-running professional tasks. Released February 5, 2026 by Anthropic, it is built for agentic coding and debugging in large codebases, long-running, multi-step autonomous agent tasks, frontier multidisciplinary reasoning (leads Humanity's Last Exam), and economically valuable knowledge work in finance and legal (GDPval-AA).
Its trade-offs are real: superseded by newer Claude Opus 4.7 and 4.8 (now a legacy model), and top-tier per-token price, and its 1M-token context shipped as beta. At $5 in / $25 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
Claude Opus 4.6 and Grok 4 overlap enough that the right pick depends on your specific job. Grok 4 costs less per token; Claude Opus 4.6 holds the larger context; and each leads in its own area — Claude Opus 4.6 for agentic coding and debugging in large codebases, 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 Claude Opus 4.6 or Grok 4 better for coding?
Public SWE-Bench figures are not available for Grok 4, so the honest test is your own repository — run an identical real bug through both. By design, Claude Opus 4.6 leans toward agentic coding and debugging in large codebases 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, Claude Opus 4.6 or Grok 4?
Grok 4 is cheaper — $5/$25 per 1M tokens vs $3/$15 per 1M tokens, roughly 1.7× apart on input.
Which has the bigger context window?
Claude Opus 4.6 — 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 Claude Opus 4.6 and Grok 4 together?
Yes — a multi-model platform like LumiChats gives you Claude Opus 4.6, 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, Claude Opus 4.6 or Grok 4?
Claude Opus 4.6 — released February 5, 2026, about 7 months after Grok 4.
Claude Opus 4.6 vs Grok 4
Anthropic · US | xAI · US · Updated June 2026
Quick verdict
Pick Claude Opus 4.6 for agentic coding and debugging in large codebases or long-running, multi-step autonomous agent tasks. 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.
Claude Opus 4.6 (Anthropic) and Grok 4 (xAI) are two of the models people most often weigh against each other in 2026. Claude Opus 4.6 is anthropic's February 2026 flagship Opus and the first Opus-class model with a 1M-token context window, built for agentic coding and long-running professional tasks. 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 1.7× cheaper on input ($3/$15 per 1M tokens vs $5/$25 per 1M tokens) — modest, but it adds up at steady volume.
▸Context window: Claude Opus 4.6 holds 3.9× more — 1M (~1,500 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: Claude Opus 4.6 is the newer model by about 7 months (released February 5, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
Spec
Claude Opus 4.6
Grok 4
Provider
Anthropic (US)
xAI (US)
Released
February 5, 2026
July 9, 2025
Context window
1M (~1,500 pages)
256K (~384 pages)
Price (in/out)
$5/$25 per 1M tokens
$3/$15 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image, code
text, image, code
SWE-Bench Verified
80.8%
Not published
MRCR v2 @ 1M
76%
Not published
Who wins what
Agentic coding and debugging in large codebases
Claude Opus 4.6
A core design strength of Claude Opus 4.6.
Long-running, multi-step autonomous agent tasks
Claude Opus 4.6
A core design strength of Claude Opus 4.6.
Frontier multidisciplinary reasoning (leads Humanity's Last Exam)
Claude Opus 4.6
A core design strength of Claude Opus 4.6.
256K context with native tool use
Grok 4
A core design strength of Grok 4.
Real-time data via X integration
Grok 4
A core design strength of Grok 4.
Strong academic reasoning
Grok 4
A core design strength of Grok 4.
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
Claude Opus 4.6
Its 1M window is about 3.9× larger, fitting roughly 1,500 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 Claude Opus 4.6, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases
→ Claude Opus 4.6
Larger 1M window fits more in one prompt.
Anyone whose priority is agentic coding and debugging in large codebases
→ Claude Opus 4.6
It is specifically built for that.
Anyone whose priority is 256k context with native tool use
→ Grok 4
That is its strongest area.
Claude Opus 4.6: where it fits
Anthropic's February 2026 flagship Opus and the first Opus-class model with a 1M-token context window, built for agentic coding and long-running professional tasks. Released February 5, 2026 by Anthropic, it is built for agentic coding and debugging in large codebases, long-running, multi-step autonomous agent tasks, frontier multidisciplinary reasoning (leads Humanity's Last Exam), and economically valuable knowledge work in finance and legal (GDPval-AA).
Its trade-offs are real: superseded by newer Claude Opus 4.7 and 4.8 (now a legacy model), and top-tier per-token price, and its 1M-token context shipped as beta. At $5 in / $25 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
Claude Opus 4.6 and Grok 4 overlap enough that the right pick depends on your specific job. Grok 4 costs less per token; Claude Opus 4.6 holds the larger context; and each leads in its own area — Claude Opus 4.6 for agentic coding and debugging in large codebases, 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 Claude Opus 4.6 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 Grok 4, so the honest test is your own repository — run an identical real bug through both. By design, Claude Opus 4.6 leans toward agentic coding and debugging in large codebases 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, Claude Opus 4.6 or Grok 4?
Grok 4 is cheaper — $5/$25 per 1M tokens vs $3/$15 per 1M tokens, roughly 1.7× apart on input.
Which has the bigger context window?
Claude Opus 4.6 — 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 Claude Opus 4.6 and Grok 4 together?
Yes — a multi-model platform like LumiChats gives you Claude Opus 4.6, 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, Claude Opus 4.6 or Grok 4?
Claude Opus 4.6 — released February 5, 2026, about 7 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.