Claude Opus 4.8, the Anthropic model in numbers

What you need to know

Claude Opus 4.8 is a language model from Anthropic, released on May 28, 2026. That makes it 5 months old as of October 22, 2026. Its weights are not published, so it only runs remotely, through the Anthropic API or partner hosts (51 listed on models.dev). It has a reasoning mode: it can "think" before answering, which helps with multi-step problems but uses more tokens, and therefore more money.

We file it under mid-range models (34 models in this category on the site).

Measured performance

According to results published by Epoch AI (checked on October 22, 2026), Claude Opus 4.8 has a capability index of 83.4 out of 100, computed on 5 benchmarks from our basket.

That puts it at #23 in our weekly model ranking.

• GPQA Diamond (PhD-level science questions): 91% — the best tracked model, Gemini 4 Argon, reaches 96.4%
• OTIS Mock AIME (competition mathematics problems): 98.3% — the best tracked model, GPT-5.5 Pro, reaches 100%
• FrontierMath (very hard research-level mathematics): 80% — the best tracked model, GPT-6 Astra, reaches 93.7%
• FrontierCode (advanced programming tasks): 46.5% — the best tracked model, Claude Opus 5.5, reaches 54.6%

Pricing and budget

Claude Opus 4.8 costs $5 per million input tokens and $25 per million output tokens (median of 51 providers, checked on October 22, 2026).

In practice, an agent task that reads 20,000 tokens and writes 2,000 costs about $0.15, or $150 for 1,000 such tasks.

That is 5.7 times the median output price of mid-range models ($4.38).

To estimate your own budget, use the agent cost calculator.

What it can do

Its context window reaches 1,000,000 tokens, roughly 1,500 pages of text at 500 words per page: enough to load a whole book or a mid-sized codebase. A single answer can run to 128,000 tokens.

It accepts as input: text, image and PDF. Its knowledge stops at January 2026: beyond that, it needs web search or your documents.

It can call tools (functions, APIs), which makes it a possible foundation for an AI agent.

What is it good for?

Given its category, Claude Opus 4.8 is mainly aimed at a balance between quality and cost, for everyday uses that do not justify a frontier model.

Its FrontierCode result (46.5%, above the median of tracked models) makes it a serious candidate for coding agents.

Its very large context window makes it worth considering for analysing large sets of documents in a single request.

Before adopting it, test it on your own examples: benchmarks measure standard tasks, not your job.

Comparable models

In the same category, the models closest to Claude Opus 4.8 are:

• Claude Opus 4.7 (Anthropic, index 83.3) — see the comparison
• Gemini 3.8 Flash (Google DeepMind, index 83.7) — see the comparison
• Gemini 3 Flash Preview (Google DeepMind, index 80.3) — see the comparison
• Grok 4.7 (xAI, index 79.9) — see the comparison