Anthropic Launches Claude Opus 4.8 With Fast Mode 2.5x Faster, 3x Cheaper

aiai-modelingai-model-releasesai-productsai-agents-coding 105 posts · 56 accounts

Anthropic launched Claude Opus 4.8, an upgrade to its top AI model that the company said offers sharper judgment, more honesty about its own progress and the ability to work independently for longer, while keeping regular pricing unchanged from Opus 4.7. Anthropic said a new Fast Mode delivers the same model at roughly 2.5 times the speed and is three times cheaper than before.

In Claude Code, Opus 4.8 defaults to a high-effort setting, with xhigh recommended for difficult or long-running tasks, and a research-preview dynamic workflows feature lets Claude plan work, run hundreds of parallel subagents and verify outputs before reporting back. Anthropic said Opus 4.8 scored 69.2% on SWE-bench Pro, up from 64.3% for Opus 4.7, and was about four times less likely to let flaws in its own code pass unremarked; Artificial Analysis said it scored 1890 on the GDPval-AA benchmark for agentic real-world work tasks, 121 points ahead of GPT-5.5 xhigh. Axios reported Anthropic expects Mythos-class models to be available to all customers in the coming weeks after stronger safeguards are developed.

From the sources (25 posts)

@daniel_mac8

Opus 4.8 confirmed in Claude Code dropdown. @rileybrown signaling it will be a big day for "both teams". We might have a double-drop ThursdAI!

@kimmonismus

HOLY, here we go: Opus 4.8 in the claude code model selector on the desctop app. Looks like its release day!!

@mark_k

Opus 4.8 is being prepared for release today by @AnthropicAI 🔥 We might witness a rare dual release by OpenAI and Anthropic. Are you READY?

@kimmonismus

What?! Opus 4.8 incoming?! Holy

@kimmonismus

Hold on, Anthropic and OpenAI releases incoming? No way

@andrewcurran_

@btibor91

Confirmed - Claude desktop app assets mention Opus 4.8

@andrewcurran_

@wesroth

Claude Code released a reliability and responsiveness update focused on fixing bugs, improving terminal behavior, and making long-running work easier to follow. The update includes a new full-screen renderer, streamed thinking and tool cal

@andrewcurran_

If Opus 4.8 does release this morning, that would mean the Anthropic release window has dropped to 42 days.

@scaling01

Tibor confirmed Opus 4.8

@testingcatalog

ANTHROPIC 🔥: Claude Opus 4.8 has been spotted in the source code. Would it drop today? 👀

@kimmonismus

Let’s go: so it’s opus 4.8 plus codex update!

@zephyr_z9

Power of RL and distillation

@scaling01

Opus 4.8 is out

@eliebakouch

hi claude opus 4.8 👋

@jukan05

CLAUDE OPUS 4.8 JUST DROPPED

@zephyr_z9

Online for me

@andrewcurran_

Opus 4.8 is live for me right now. Anthropic's release window is now 42 days.

@tradfi

*ANTHROPIC LAUNCHED CLAUDE OPUS 4.8, FEATURING 3X CHEAPER "FAST MODE" PRICING FOR USERS

@scaling01

Claude Opus 4.8 Benchmarks

@scaling01

Claude 4.8 Opus System Card

@yuchenj_uw

Opus 4.8 is out. God damn!

@wallstengine

Anthropic just launched Claude Opus 4.8, including a new Fast Mode with 3x cheaper pricing for users.

@andrewcurran_

Lisan already found the system card:

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