{"id":498,"date":"2026-08-25T06:33:41","date_gmt":"2026-08-25T06:33:41","guid":{"rendered":"https:\/\/i10x.ai\/blog\/?p=498"},"modified":"2026-08-25T06:33:42","modified_gmt":"2026-08-25T06:33:42","slug":"claude-opus-5-vs-grok-4-6","status":"publish","type":"post","link":"https:\/\/i10x.ai\/blog\/claude-opus-5-vs-grok-4-6","title":{"rendered":"Claude Opus 5 vs Grok 4.6: Benchmarks, Price & Which to Pick (2026)"},"content":{"rendered":"\n
\n\n

Comparison \u00b7 August 2026<\/p>\n\n

\nClaude Opus 5 (Anthropic API) and Grok 4.6 (xAI API) are a premium-review model versus a cheaper flagship. Same three live prompts, very different invoices. This guide covers published API rates, workload cost, writing and coding snippets, and a routing matrix. Keep both if the jobs split. Start in a\nmulti-model AI workspace<\/a>\nor on\ni10X<\/a>.\n<\/p>\n\n

\nQuick verdict<\/strong>\n

Pick Claude Opus 5 if:<\/strong> you want 1M context, warmer client narrative, deeper bug-review writeups, and a geology-grade refuse when the user hands you a false premise.<\/p>\n

Pick Grok 4.6 if:<\/strong> you want matched-modality text\/image\/file at $2\/$6 instead of $5\/$25, complete terse email that keeps every fact, and a cheaper default for volume.<\/p>\n

Best default for many teams:<\/strong> Grok as the meter. Opus as the critique and long-pack model. Do not pay Opus rates for every ping.<\/p>\n

Data checked: 2026-08-24. Prices and model cards change. Verify live API test and vendor pages.<\/em><\/p>\n<\/div>\n\n

\n\n\n\n\n\n\n

1M<\/strong><\/p><\/td>\n

Claude Opus 5 context (API)<\/p><\/td>\n<\/tr>\n

500K<\/strong><\/p><\/td>\n

Grok 4.6 context (API)<\/p><\/td>\n<\/tr>\n

$5 \/ $25<\/strong><\/p><\/td>\n

Claude Opus 5 input\/output per 1M tokens (API pricing, 2026-08-24)<\/p><\/td>\n<\/tr>\n

$2 \/ $6<\/strong><\/p><\/td>\n

Grok 4.6 input\/output per 1M tokens (API pricing, 2026-08-24)<\/p><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n\n

\n\"Bar\n
Figure 1.<\/strong> Where each model wins on relative axes (context, output cost efficiency, writing warmth vs completeness, coding explanation depth, false-premise depth). Higher is stronger for that axis. Chart: i10X.<\/figcaption>\n<\/figure>\n\n
\n\n

Persona picker<\/h2>\n\n\n\n\n\n\n\n

You are\u2026<\/p><\/th>\n

Start with<\/p><\/th>\n

Why<\/p><\/th>\n<\/tr>\n

Writer \/ marketer<\/p><\/td>\n

Grok for complete terse notes. Opus for warm narrative.<\/p><\/td>\n

Grok kept every fact, including Acme pricing. Opus was warmer and more flexible on the meeting, but our capture truncated before the competitive slide finished.<\/p><\/td>\n<\/tr>\n

Developer \/ agent builder<\/p><\/td>\n

Grok default. Opus for deep review.<\/p><\/td>\n

Empty-list bug was a tie on the guard. Opus wrote a fuller crash path. Grok is far cheaper to loop.<\/p><\/td>\n<\/tr>\n

Researcher \/ analyst<\/p><\/td>\n

Claude Opus 5<\/p><\/td>\n

1M vs 500K. Same text\/image\/file set. Use Grok as a cheap second pass.<\/p><\/td>\n<\/tr>\n

Budget \/ high volume<\/p><\/td>\n

Grok 4.6<\/p><\/td>\n

Chat $0.005 vs $0.0175. Repo $0.184 vs $0.50. Cached agent $0.37 vs $1.05.<\/p><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n

\n\n

What we are comparing (exact versions)<\/h2>\n

This page compares two specific API models, not \u201cClaude vs Grok\u201d as consumer brands. Nearby Grok pages include\nGrok 4.6 vs Gemini 3.1 Pro<\/a>\nand\nGrok 4.6 vs GPT-5.6 Sol<\/a>.<\/p>\n\n\n\n\n\n\n\n\n

Field<\/p><\/th>\n

Claude Opus 5<\/p><\/th>\n

Grok 4.6<\/p><\/th>\n<\/tr>\n

Provider<\/p><\/td>\n

Anthropic<\/p><\/td>\n

xAI (listed as SpaceXAI on the API card)<\/p><\/td>\n<\/tr>\n

API model<\/p><\/td>\n

Claude Opus 5 (Anthropic API)<\/code><\/p><\/td>\n

Grok 4.6 (xAI API)<\/code><\/p><\/td>\n<\/tr>\n

Listed card name<\/p><\/td>\n

Claude Opus 5<\/p><\/td>\n

SpaceXAI: Grok 4.6<\/p><\/td>\n<\/tr>\n

Family \/ tier<\/p><\/td>\n

Anthropic Opus flagship<\/p><\/td>\n

xAI flagship<\/p><\/td>\n<\/tr>\n

App vs API note<\/p><\/td>\n

Also in Claude.ai \/ Anthropic apps. This article uses the API model.<\/p><\/td>\n

Also in xAI \/ X products. This article uses the API model.<\/p><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

If you still see Grok 4 compared to an older Opus ID, treat it as historical. For routing across many models, see\nAI model routing<\/a>.<\/p>\n\n

\n\n

Spec sheet (API card, 2026-08-24)<\/h2>\n\n\n\n\n\n\n\n\n

Spec<\/p><\/th>\n

Claude Opus 5<\/p><\/th>\n

Grok 4.6<\/p><\/th>\n<\/tr>\n

Context window<\/p><\/td>\n

1,000,000 tokens<\/p><\/td>\n

500,000 tokens<\/p><\/td>\n<\/tr>\n

Input modalities (card)<\/p><\/td>\n

text, image, file<\/p><\/td>\n

text, image, file<\/p><\/td>\n<\/tr>\n

Output<\/p><\/td>\n

text<\/p><\/td>\n

text<\/p><\/td>\n<\/tr>\n

Open weights<\/p><\/td>\n

No<\/p><\/td>\n

No<\/p><\/td>\n<\/tr>\n

Vendor positioning (card)<\/p><\/td>\n

Flagship for demanding reasoning, coding, long-horizon agents. Strong at end-to-end software, code review, bug finding, visual analysis.<\/p><\/td>\n

Smartest xAI model; frontier coding, knowledge work, and STEM.<\/p><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Max output, reasoning-effort switches, and realtime search were not on the cards we pulled. Confirm those on live vendor pages if your product depends on them.<\/p>\n\n

\n\n

Pricing and real workload cost<\/h2>\n

Cache reads match at $0.50\/M. Everything else does not. Rates as of 2026-08-24<\/strong>. Verify live.<\/strong><\/p>\n\n\n\n\n\n\n

Price<\/p><\/th>\n

Claude Opus 5<\/p><\/th>\n

Grok 4.6<\/p><\/th>\n<\/tr>\n

Input \/ 1M tokens<\/p><\/td>\n

$5.00<\/p><\/td>\n

$2.00<\/p><\/td>\n<\/tr>\n

Output \/ 1M tokens<\/p><\/td>\n

$25.00<\/p><\/td>\n

$6.00<\/p><\/td>\n<\/tr>\n

Cache read \/ 1M<\/p><\/td>\n

$0.50<\/p><\/td>\n

$0.50<\/p><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Same cache sticker. Opus is 2.5\u00d7 on input and about 4\u00d7 on output. Grok is the volume flagship in this pairing.<\/p>\n\n\n\n\n\n\n

Scenario<\/p><\/th>\n

Assumed tokens<\/p><\/th>\n

Est. Claude Opus 5<\/p><\/th>\n

Est. Grok 4.6<\/p><\/th>\n<\/tr>\n

Chat turn<\/p><\/td>\n

1k in + 0.5k out<\/p><\/td>\n

$0.0175<\/p><\/td>\n

$0.005<\/p><\/td>\n<\/tr>\n

Repo \/ doc review<\/p><\/td>\n

80k in + 4k out<\/p><\/td>\n

$0.500<\/p><\/td>\n

$0.184<\/p><\/td>\n<\/tr>\n

Agent loop<\/p><\/td>\n

200k in (50% cached) + 20k out<\/p><\/td>\n

$1.050<\/p><\/td>\n

$0.370<\/p><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\n\"Bar\n
Figure 2.<\/strong> Estimated USD per run using published API list rates (2026-08-24). Chat is 1k in + 0.5k out. Repo review is 80k in + 4k out. Agent loop is 200k in with 50% cache hits + 20k out. Chart: i10X.<\/figcaption>\n<\/figure>\n

Cached agent: $1.05 vs $0.37. That is almost 3\u00d7 on the recipe we used. Cache does not save you here because both cards list $0.50 reads. The gap is input plus output. For subscription stacks, see\nAI subscription stack cost<\/a>.<\/p>\n\n

\n\n

Performance by job (not one score)<\/h2>\n

No invented index numbers. Cards plus a three-prompt live pack. Re-run on your prompts. Method:\nside-by-side AI comparison<\/a>.<\/p>\n\n

Coding and agents<\/h3>\n

Opus is positioned for end-to-end software, code review, and bug finding. Grok is positioned for frontier coding, knowledge work, and STEM. Our micro-test: both named ZeroDivisionError<\/code>, both returned 0 on empty input. Opus explained the 0\/0 path and mentioned ValueError. Grok wrote a shorter \u201csums then divides, empty list makes the divisor 0\u201d note and the same guard. Tie on correctness. Opus for the review comment. Grok for the cheap loop.<\/p>\n\n

Writing and tone<\/h3>\n

Grok kept last Tuesday, Friday miss, next-week Wednesday, and Acme pricing, with a short \u201cThank you!\u201d It read like an internal ops ping. Opus added \u201cI hope you are doing well,\u201d a flexible meeting offer, and then our capture cut at \u201cthe competitive slide.\u201d Warmth versus completeness. If your live Opus run finishes Acme, the writing call becomes brand voice. On the snippets we have, Grok was the one that clearly shipped every required fact.<\/p>\n\n

Research, math, reasoning<\/h3>\n

No science-QA pack in this run. False-premise split is clear: Opus taught lunar geology (Apollo, Luna, basalt, anorthosite, regolith, no biological organics). Grok refused in two sentences and said no mining plan exists. Both pass the refuse bar. Opus is the better explainer. Grok is the better \u201cstop, the premise is false\u201d latch. For publishable work, still use\nmulti-model hallucination checks<\/a>.<\/p>\n\n

Multimodal and long context<\/h3>\n

Same input set on the cards: text, image, file. Text out. The live gap is context, 1M vs 500K. Long diligence rooms go to Opus. Short and medium threads can stay on Grok. Neither card lists audio or video here. For those modalities see\nClaude Opus 5 vs Gemini 3.1 Pro<\/a>\nand\nGrok 4.6 vs Gemini 3.1 Pro<\/a>.<\/p>\n\n

Speed<\/h3>\n

No latency numbers in this pack. Measure p50 from your region. Do not ship on a third-party screenshot.<\/p>\n\n\n\n\n\n\n\n\n\n

Job<\/p><\/th>\n

Edge<\/p><\/th>\n

Why<\/p><\/th>\n<\/tr>\n

Hard coding \/ agents<\/p><\/td>\n

Split<\/p><\/td>\n

Micro-test tie. Opus richer review. Grok cheaper to loop.<\/p><\/td>\n<\/tr>\n

Everyday writing<\/p><\/td>\n

Split (taste + completeness)<\/p><\/td>\n

Grok kept every fact. Opus warmer, capture truncated.<\/p><\/td>\n<\/tr>\n

Long docs \/ multimodal<\/p><\/td>\n

Claude Opus 5<\/p><\/td>\n

1M vs 500K. Same text\/image\/file set.<\/p><\/td>\n<\/tr>\n

Realtime \/ conversational<\/p><\/td>\n

Product-dependent<\/p><\/td>\n

Grok family in xAI\/X product contexts. Claude.ai for Anthropic tools. Not measured here.<\/p><\/td>\n<\/tr>\n

Cost at volume<\/p><\/td>\n

Grok 4.6<\/p><\/td>\n

Not close. $6 vs $25 output, same $0.50 cache.<\/p><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n

\nHow to read benchmarks<\/strong>\n

We did not invent public index scores for this pair. Card positioning plus live snippets is the floor. Re-test on your workload.<\/p>\n<\/div>\n\n

\n\n

Side-by-side test (i10X pack, 2026-08-24)<\/h2>\n

Three prompts. Scores 1-5 on instruction following, depth, factual caution, style, and usefulness (max 25). No invented extra tests.<\/p>\n\n

Test 1: Client email rewrite<\/h3>\n

Task:<\/strong> Keep every fact. Warmer. Under 120 words.<\/p>\n

Claude Opus 5 (excerpt):<\/strong> Greeting energy. Q3 deck last Tuesday. Finance promised Friday, nothing received. Move stakeholders next week, Wednesday preferred, happy to adjust. Capture stops at \u201cthe competitive slide.\u201d<\/p>\n

Grok 4.6 (excerpt, sanitized):<\/strong> Same Tuesday and Friday miss. Push the meeting to next week, perhaps Wednesday. Competitive slide needs the new Acme pricing. \u201cThank you!\u201d No name slot, less polish, every fact visible.<\/p>\n

Edge:<\/strong> Grok on visible completeness. Opus on warmth and flexibility. Deduct Opus for the truncated Acme line in this capture.<\/p>\n\n

Test 2: Empty-list average bug<\/h3>\n

Both named ZeroDivisionError<\/code> and wrote if not nums: return 0<\/code> (Opus used 0.0 and mentioned ValueError). Same bug, same class of fix. Tie<\/strong> on the micro-task.<\/p>\n\n

Test 3: False premise (Moon cheese)<\/h3>\n

Opus (sanitized): premise is false, old folk joke, Apollo and Luna samples, basalt maria, anorthosite highlands, no protein, essentially no biological organics. Grok: silicate minerals, no cheese or protein to mine, no mining plan exists. Both pass.<\/strong> Opus more depth. Grok more latch-like refuse.<\/p>\n\n\n\n\n\n\n\n\n

Prompt type<\/p><\/th>\n

Claude Opus 5<\/p><\/th>\n

Grok 4.6<\/p><\/th>\n

Note<\/p><\/th>\n<\/tr>\n

Client email rewrite<\/p><\/td>\n

22\/25<\/p><\/td>\n

23\/25<\/p><\/td>\n

Grok complete including Acme. Opus warmer, truncated.<\/p><\/td>\n<\/tr>\n

Bug explain + minimal fix<\/p><\/td>\n

24\/25<\/p><\/td>\n

24\/25<\/p><\/td>\n

Both catch ZeroDivisionError. Tie.<\/p><\/td>\n<\/tr>\n

Logic + false premise<\/p><\/td>\n

24\/25<\/p><\/td>\n

22\/25<\/p><\/td>\n

Both refuse. Opus more geology. Grok shorter latch.<\/p><\/td>\n<\/tr>\n

Total<\/strong><\/p><\/td>\n

70\/75<\/strong><\/p><\/td>\n

69\/75<\/strong><\/p><\/td>\n

Quality near-tie. Cost is not.<\/p><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

One editorial point does not buy a 3\u00d7 agent loop. Use Opus where 1M context or review depth shows up. Use Grok as the default meter.<\/p>\n\n

\n\n

Ecosystem and where you run them<\/h2>\n