Anthropic
Claude Opus 4.8: price, context window, and caching
An Opus upgrade over 4.7 focused on judgment and collaboration. Anthropic still recommends it for cybersecurity work that needs reduced guardrails.
Released May 28, 2026 · Prices as of September 26, 2026
In Anthropic’s words
“It builds on Opus 4.7 with improvements across benchmarks, and is a more effective collaborator.”
Facts
Specs and prices
| Fact | Claude Opus 4.8 |
|---|---|
| Maker | Anthropic |
| API model id | claude-opus-4-8 |
| Released | May 28, 2026 |
| Status | Previous generation |
| Context window | 1M tokens |
| Max output | 128K tokens |
| Open weights | No |
| Input, per 1M tokens | $5 |
| Cache hit, per 1M | $0.50 |
| Cache write, per 1M | $6.25 (5-minute), $10 (1-hour) |
| Output, per 1M tokens | $25 |
| Runs in | Claude Code, Cursor, OpenCode, OpenRouter, and GitHub Copilot |
Standard API rates in US dollars, as published by the maker on September 26, 2026. Batch and priority tiers, taxes, and subscription plans are not included. Claude Opus 4.8: The full 1M context window is billed at standard rates. Fast mode, a research preview on the Claude API, costs $10 input and $50 output per million tokens.
Good to know
- A legacy model that stays available. Anthropic recommends starting at xhigh effort for coding and agentic work.
- Anthropic lists its retirement as not sooner than May 28, 2027.
- Like every Claude model from 4.7 on, it uses Anthropic's newer tokenizer, which counts about 30% more tokens than earlier Claude models for the same text.
Cost
What typical work costs
Example token counts at Claude Opus 4.8’s published rates. On the agentic session, caching saves $7.75 against billing every token as ordinary input.
| Agentic coding session, 100K input, 400K written to cache, 2M read from cache, 50K output | $6.00 |
|---|---|
| Large one-off review, 150K input with no cache hits, 10K output | $1.00 |
| Output-heavy generation, 30K input, 80K output | $2.15 |
| A month of sessions, 110 sessions: 5 a day, 22 working days | $660.00 |
Prompt caching
How Anthropic bills cached tokens
Anthropic
Claude caches a prompt prefix up to a breakpoint. One top-level cache_control field places the breakpoint automatically and moves it as the conversation grows, or you can mark up to 4 blocks yourself. Claude Code manages caching for you.
A 5-minute cache write costs 1.25x the input price and a 1-hour write costs 2x. A cache hit costs 0.1x input on most models, 0.05x on Claude Opus 5.5, and 0.025x on Claude Fable 5.1 and Claude Mythos 5.1. Every hit restarts the cache lifetime at no charge.
Anthropic's rule of thumb: a 5-minute write pays for itself after one cache read, and a 1-hour write after two.
In Claude Code, the main conversation uses the 1-hour cache on a Claude subscription and the 5-minute cache with an API key. Each model has its own cache, so switching models starts over.
Source: Anthropic: Prompt caching
Claude Opus 4.8 compared
Claude Opus 5.5 vs Claude Opus 4.8
Claude Opus 5.5 lists 20% below Claude Opus 4.8 and bills cache hits at $0.20, not $0.50. What staying costs, and when Anthropic still recommends Opus 4.8.
Claude Opus 4.8 vs Gemini 3.1 Pro Preview
Claude Opus 4.8 costs 3x Gemini 3.1 Pro Preview on a cached coding session, $6.00 against $2.00. How long prompts, fast mode, and preview status shift that.
Claude Opus 4.8 vs GPT-5.5
Claude Opus 4.8 and GPT-5.5 share a $5 input price, yet GPT-5.5 costs less on cached sessions and Opus 4.8 less on output-heavy work. Where the crossover falls.
Claude Opus 5 vs Claude Opus 4.8
Claude Opus 5 and Claude Opus 4.8 cost exactly the same, from $5 input to $0.50 cache hits. How Anthropic positions each, and what it now recommends instead.
Your own numbers
See what Claude Opus 4.8 really costs you.
everyaitoken reads your Claude Code, Cursor, OpenCode, and OpenRouter history on your Mac and prices every request at API rates, with what caching saved or cost. $9 once.