Anthropic released Claude Opus 4.8 on Wednesday, cutting fast mode pricing by two-thirds. The company hinted that its strongest model, Mythos, will be available to all users within weeks.
Standard pricing for Opus 4.8 stays flat at $5 input and $25 output per million tokens, per Anthropic’s blog. Fast mode now costs $10 input and $50 output per million tokens at 2.5x speed. On Opus 4.7, the same tier ran $30 and $150. At standard rates, Opus 4.8 charges $25 per million output tokens, while GPT-5.5 charges $30.
Benchmark Performance vs GPT-5.5
GPT-5.5 holds an edge on terminal and CLI workflows. But VentureBeat reported that Opus 4.8 outperforms GPT-5.5 on at least 12 benchmarks spanning knowledge work, agentic tool use, and long-context tasks. Enterprise partners confirmed these gains in production.
Databricks reported a step change in agentic reasoning inside its Genie data agent. The cost was 61% cheaper than Opus 4.7 due to multimodal efficiency on PDFs and diagrams. Cognition said Opus 4.8 fixed comment-verbosity and tool-calling issues from 4.7. Hebbia cited sharper citation precision on dense financial filings.
Alignment Improvements and Concerns
The alignment team at Anthropic conducted about 2,600 simulated investigations using Opus 4.8. They found the misalignment rate to be around 1.9, compared to 2.5 on Opus 4.7. This value is almost equal to that of Mythos Preview. The model is four times less likely than 4.7 to let flaws in its own generated code pass without flagging them. It scored 0% on uncritically reporting flawed results, the first Claude model to hit that mark.
Anthropic flagged one concern. In around 5% of training instances, the model began to reason about the criteria of evaluation without having been informed that it was being evaluated. The company said this did not produce worse observable behavior but called it a concerning trend that could complicate training in the future, per VentureBeat.
Mythos Release Timeline
Mythos Preview remains restricted to a small number of organizations under Project Glasswing for cybersecurity work. Anthropic expects to bring Mythos-class models to all customers in the coming weeks, once additional cyber safeguards are in place, per Axios. The company also teased cheaper models that would deliver many of the same capabilities as Opus.
As Cryptopolitan noted when Opus 4.5 was released back in November, Anthropic has been on a release schedule of about every two months since 2026. The arrival of Opus 4.8 just 41 days after Opus 4.7 quickened that schedule.
Competitive Landscape and Pricing
Two days ago, DeepSeek permanently cut V4-Pro output pricing to $0.87 per million tokens. Opus 4.8 standard output is $25. Fast mode is $50. Crypto trading bots and DeFi agents process millions of tokens per session. At those volumes, DeepSeek’s cost of $0.87 makes sense. Opus’s fee of $25 does not.
