Grok 4 vs Claude Opus 4.8: Which Should You Use?

Grok 4 and Claude Opus 4.8 were built with different priorities. xAI released Grok 4, also written as Grok-4 or grok4, on July 9, 2025. It launched as the company's flagship reasoning model, offering native web search, code execution, and a 256,000-token context window. Anthropic released Claude Opus 4.8 on May 28, 2026. It's a general-purpose coding model that powers Claude Code and costs $5 per million input tokens and $25 per million output tokens.

Since then, xAI has released Grok 4.3, 4.5, and 4.6, so Grok 4 is no longer its flagship. Opus 4.8 remains Anthropic's current mid-tier model, while the more expensive Claude Fable 5 sits above it for the most demanding work. For a comparison with xAI's current flagship, see Grok 4.6 vs Claude Opus 4.8.

Below, we compare pricing, context windows, published benchmarks, and compliance to help you decide which model, or which generation of Grok, best fits your workload.

Grok 4 vs. Claude Opus 4.8: Side-by-Side

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Release Timing and How Each Model Is Reached

Grok 4 launched July 9, 2025 as xAI's flagship reasoning model. It is reachable through a SuperGrok or X Premium+ consumer subscription, roughly $8 to $40 per month across tiers, or through xAI's developer API.

Claude Opus 4.8 launched May 28, 2026 as Anthropic's strong general-purpose coder, running on the Anthropic API, Enterprise plans, and Claude Code. It sits below Claude Fable 5 in Anthropic's current lineup, positioned for high-volume, everyday coding and agentic work rather than the single hardest problems.

One model is nearly a year older than the other. xAI has released three Grok generations since 4, a gap worth naming up front rather than treating this as a same-era matchup.

• Grok 4: released July 9, 2025. SuperGrok/X Premium+ or API access
• Claude Opus 4.8: released May 28, 2026. Anthropic API, Enterprise, Claude Code
• xAI has shipped Grok 4.3, 4.5, and 4.6 since Grok 4's release

Pricing: Opus 4.8 Publishes a Rate Card, Grok 4 Does Not

Claude Opus 4.8's per-token pricing is public: $5 per million input tokens and $25 per million output tokens, about half the price of Anthropic's top tier, Claude Fable 5.

xAI has not published a per-token API rate for the original Grok 4 in the materials reviewed for this comparison. Consumer access runs through SuperGrok or X Premium+ subscriptions instead. As a directional reference only, a later release, Grok 4.3, is priced at $1.25 input and $2.50 output per million tokens. Confirm the current rate for Grok 4 specifically with xAI before budgeting an API integration against it.

Both models support prompt caching, which can meaningfully cut input costs on high-repetition workloads regardless of which you pick.

• Claude Opus 4.8: $5 input / $25 output per million tokens
• Grok 4: API token price not published. SuperGrok/X Premium+ is $8 to $40/month
• Directional reference: Grok 4.3 (a later release) runs $1.25 input / $2.50 output per million tokens

→ Compare per-token pricing for every AI model

Grok 4 vs Claude Opus 4.8 Benchmarks: What's Actually Published

Neither xAI nor Anthropic has published a same-day, apples-to-apples benchmark suite pitting these two exact models against each other. Treat any comparison here as directional rather than a verified head-to-head.

On SWE-bench Verified, a widely cited coding benchmark, four recent reference points stand out. Claude Opus 4.8 scores about 88.6%, GPT-5 about 74%, Grok 4 about 75%, and Gemini 2.5 Pro about 71%. Opus 4.8 leads this specific set by a wide margin, though the models were not run on a shared, same-day evaluation.

Until both vendors publish a matched benchmark run, the more reliable signal is a short pilot on your own tasks: coding, research, or drafting representative of your real workload.

• Claude Opus 4.8: ~88.6% on SWE-bench Verified.
• Grok 4: ~75% on SWE-bench Verified.
• GPT-5: ~74% on SWE-bench Verified, for reference.
• Gemini 2.5 Pro: ~71% on SWE-bench Verified, for reference.

Compliance: Opus 4.8 Has the More Documented Coverage

Claude Opus 4.8 ships with SOC 2, ISO 27001, and ISO 42001 certifications plus an available HIPAA BAA on the API and Enterprise plans. That is the same compliance coverage as its more expensive sibling, Claude Fable 5.

xAI states Grok 4 is SOC 2 Type 2 compliant and offers a Zero Data Retention (ZDR) option for enterprise accounts. A BAA for healthcare data is available on request through xAI's questionnaire, alongside the ZDR-enabled API. It is not automatic.

For a regulated SMB weighing the two, Opus 4.8's certifications are more thoroughly documented in public materials. Confirm Grok 4's current certification scope and BAA terms on xAI's security FAQ before sending protected data.

• Claude Opus 4.8: SOC 2, ISO 27001, ISO 42001, HIPAA BAA available
• Grok 4: xAI-stated SOC 2 Type 2, Zero Data Retention option, BAA on request
• Neither model's regulated-data path is automatic on the consumer product. Both require the enterprise/API route

How to Choose Between Grok 4 and Claude Opus 4.8

Choose Claude Opus 4.8 for everyday coding and agentic workflows, published and predictable pricing, and the more thoroughly documented compliance stack. It is the safer default for most regulated SMBs today.

Choose Grok 4 if your workflow specifically needs real-time web or X-data search and native code execution in one tool, and you are already invested in the xAI ecosystem.

If you are starting fresh rather than maintaining an existing Grok 4 integration, evaluate xAI's current flagship instead: see Grok 4.6 vs Claude Opus 4.8 for the up-to-date matchup.

• Pick Opus 4.8: coding, agentic workflows, documented compliance, published pricing
• Pick Grok 4: real-time web/X search paired with code execution, existing xAI integration
• Starting fresh: compare Opus 4.8 against Grok 4.6, xAI's current flagship, instead

Who Neither Model Fits Well

Claude Opus 4.8 is a poor fit for a workload that genuinely needs live web or X-platform data pulled into the answer. Anthropic has not published the same native real-time search and tool-use pattern for Opus 4.8 that xAI ships with Grok 4. A brand-monitoring or current-events workflow is better served elsewhere.

Grok 4 is a poor fit for a regulated buyer that needs a mature, well-documented compliance package on day one. Its enterprise paperwork exists, but it is thinner in the public materials reviewed here than Anthropic's SOC 2, ISO 27001, and ISO 42001 coverage for Opus 4.8. A healthcare or financial-services team that cannot tolerate ambiguity should default to the better-documented option.

Neither model is the right starting point for a team that only needs occasional, low-volume drafting help. A lower-cost general chat plan covers that case without the API integration work either model requires.

What Would Change This Verdict

This verdict would flip if xAI published a clear per-token API rate and a fuller public compliance package for Grok 4 specifically. The pricing and documentation gap is the main reason Opus 4.8 reads as the safer default here, and closing that gap removes the reason.

It would also flip on a workload where Grok 4's real-time web and X-data access is the deciding requirement. Opus 4.8 has no equivalent native feature for that specific job.

If you measure your own tasks and Grok 4 comes out ahead of Opus 4.8's SWE-bench Verified score of about 88.6%, let that result move your pick. The published reference points favor Opus 4.8 overall, but your own test outranks them.

How to use Grok 4 and Claude Opus 4.8

You do not run hosted models like Grok 4 and Claude Opus 4.8 on your own hardware — you reach them through a tool, and the same one can usually drive both. Picking that tool is most of the setup.

The fastest way to put Grok 4 and Claude Opus 4.8 to work day to day is inside an AI IDE, and Cursor is the most popular — it supports both directly, so you can be working in minutes. The maker's own option is Claude Code for Claude Opus 4.8, if you want the native experience. Prefer a different editor? Windsurf, Zed, and GitHub Copilot drive these models too.

The Verdict

Claude Opus 4.8 is the stronger default for most businesses. It offers a published rate card, the more thoroughly documented compliance stack, and the leading published SWE-bench Verified score in this comparison.

Grok 4 still earns its keep for a narrower job: real-time web and X-data search paired with native code execution. But it is xAI's original release from July 2025, and three newer Grok versions (4.3, 4.5, 4.6) have shipped since. If you are not already committed to Grok 4, evaluate the current-generation Grok 4.6 against Opus 4.8 instead.

Many teams that keep an older Grok 4 integration route their hardest coding work to Opus 4.8. They reserve Grok 4 for the real-time search tasks it still does well, rather than picking one model for everything.