Claude Opus 4.8 vs Grok 4.6

Anthropic · US  |  xAI · US · Updated June 2026

Quick verdict

Pick Claude Opus 4.8 for agentic coding and multi-file debugging or long autonomous tasks. 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.

Claude Opus 4.8 (Anthropic) and Grok 4.6 (xAI) are two of the models people most often weigh against each other in 2026. Claude Opus 4.8 is the agentic-coding and judgment leader — highest SWE-Bench Pro score ever recorded at launch. 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

Side-by-side specs

SpecClaude Opus 4.8Grok 4.6
ProviderAnthropic (US) xAI (US)
ReleasedMay 28, 2026 August 12, 2026
Context window1M (~1,500 pages) 500K (~750 pages)
Price (in/out)$5/$25 per 1M tokens $2/$6 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image, code text, image, code
SWE-Bench Verified88.6% Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Agentic coding and multi-file debugging

Claude Opus 4.8

Grok 4.6 is comparatively weak here — coding gains (DeepSWE 65.9, APEX-Agents 57.5) are xAI's own numbers, not independently reproduced

Long autonomous tasks

Claude Opus 4.8

Its 1M window holds about 2× more than Grok 4.6's 500K in a single prompt.

Honest uncertainty flagging

Claude Opus 4.8

The agentic-coding and judgment leader — highest SWE-Bench Pro score ever recorded at launch — and it carries the larger 1M context.

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 Claude Opus 4.8 ($5/$25 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

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.

$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 is the newer of the two.

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

Claude Opus 4.8

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 Claude Opus 4.8, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Claude Opus 4.8

Larger 1M window fits more in one prompt.

Anyone whose priority is agentic coding and multi-file debugging

Claude Opus 4.8

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.

Claude Opus 4.8: where it fits

The agentic-coding and judgment leader — highest SWE-Bench Pro score ever recorded at launch. Released May 28, 2026 by Anthropic, it is built for agentic coding and multi-file debugging, long autonomous tasks, honest uncertainty flagging, and professional writing and reasoning.

Its trade-offs are real: highest per-token price of the frontier tier, and not the cheapest for high-volume work. At $5 in / $25 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

Claude Opus 4.8 and Grok 4.6 overlap enough that the right pick depends on your specific job. Grok 4.6 costs less per token; Claude Opus 4.8 holds the larger context; and each leads in its own area — Claude Opus 4.8 for agentic coding and multi-file debugging, 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 Claude Opus 4.8 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.

See pricing

Frequently asked questions

Is Claude Opus 4.8 or Grok 4.6 better for coding?

Public SWE-Bench figures are not available for Grok 4.6, so the honest test is your own repository — run an identical real bug through both. By design, Claude Opus 4.8 leans toward agentic coding and multi-file debugging 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, Claude Opus 4.8 or Grok 4.6?

Grok 4.6 is cheaper — $5/$25 per 1M tokens vs $2/$6 per 1M tokens, roughly 2.5× apart on input.

Which has the bigger context window?

Claude Opus 4.8 — 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 Claude Opus 4.8 and Grok 4.6 together?

Yes — a multi-model platform like LumiChats gives you Claude Opus 4.8, 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, Claude Opus 4.8 or Grok 4.6?

Grok 4.6 — released August 12, 2026, about 3 months after Claude Opus 4.8.

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.