Claude Opus 4.8

Closed weights Anthropic May 2026

No estimate

No hardware requirements for this model

The weights for this model have not been published, so it cannot be downloaded or run on your own hardware at any size. It is reachable only through its provider, and no graphics card changes that.

On record

Full specification

Everything on record for this model. Most of it describes how it was trained rather than how it runs — useful context for judging how much work went into it, and how it compares with models built at a different scale.

Origin

Who built this model, where, and when it was published.

Organisation
Anthropic
Organisation type
Industry
Country
United States of America
Published
28 May 2026

What it does

The problem areas the model was built for. A model can carry several of each.

Domain
Language
Task
Language modeling/generation

Size

How large the model is and how much data it was trained on. Parameters are the figure that decides whether it fits on a given graphics card.

Training data
tokens

Availability

Whether you can obtain the model and run it on your own hardware, which is what decides if any of the graphics-card figures on this page apply.

Weights
Closed — provider access only
Model access
API access

How it is classified

Labels the source dataset applies when tracking notable models, and how confident it is in the entry.

Why it is tracked
Significant use
Record confidence
Confident

Sources

Where this record came from and when it was last checked.

Reference
Introducing Claude Opus 4.8
Last updated
21 July 2026

What the numbers mean

Where it came from

Claude Opus 4.8 was published by Anthropic, in the country recorded as United States of America, during May 2026. It comes out of an organisation categorised as industry.

It works in the domain of Language, and is recorded as performing the task of language modeling/generation.

Because the weights are not available, none of the hardware figures elsewhere on this site apply to it.

How it was trained

The reason it appears in this catalogue at all: significant use.

Answers

Claude Opus 4.8 — common questions

01

Claude Opus 4.8— is it open source?

No. Its weights have not been published, so it exists only as a service controlled by its owner.

02

Claude Opus 4.8— how many parameters does it have?

No parameter count has been published for it, which is why no memory or speed figure appears on this page.

03

Claude Opus 4.8— who created it?

It was published by Anthropic, based in United States of America, an organisation categorised as industry.

04

Claude Opus 4.8— when was it released?

It was published in May 2026.

05

Claude Opus 4.8— what is it used for?

It works in the domain of Language, and is recorded as handling the task of language modeling/generation. Models frequently carry more than one of each, and the tags describe purpose rather than capability limits.

06

Claude Opus 4.8— what GPU do I need to run it?

None. This is a closed model — its weights were never published, so it cannot be downloaded or run on your own hardware at any price. It is reachable only through its provider.

Source

Original publication

Record last updated 21 July 2026

The other direction

Looking at it from the other side?

This page starts from the model. If you already own a card and want to know everything it will run, start from the hardware instead.