# Claude Opus 4.8 pricing, and why five versions cost the same > Claude Opus 4.8 pricing is $5.00 per million input and $25.00 output, identical to Opus 4.5, 4.6, 4.7 and Opus 5. Why the version upgrade is free. URL: https://getculpa.com/claude-opus-4-8-pricing Last reviewed: 2026-08-01 Rates effective: 2026-07-02 ## Answer Claude Opus 4.8 pricing is $5.00 per million input tokens and $25.00 per million output tokens, and Opus 4.5, 4.6, 4.7 and the newer Opus 5 all bill identically. So an Opus version pin saves nothing at all. Culpa, a local-first LLM cost, margin, and forecast ledger, records the model version on every call, so a stale pin shows up as a fact. ## Why this happens Five Opus versions share one rate in this price book, Opus 4.5 through 4.8 plus Opus 5, which produces a specific and common waste. Teams pin an older Opus version to avoid the risk of a change, and assume the pin is also saving money. It isn't. The rate is identical, so the pin buys behavioural stability and nothing else. Meanwhile the older pin often carries older prompt habits, usually a fatter system prompt written for a model that needed more steering. ## What this usually looks like - Production is pinned to an Opus version from several releases ago and nobody remembers deciding that. - The pin is justified as a cost measure, which the rate card doesn't support. - Different services in the same product run different Opus versions, with no cost difference between them. - The prompt attached to the older pin is noticeably longer than the one used elsewhere. ## Common mistakes - Keeping an older Opus pin to save money. Why it hurts: All five versions bill the same, so the pin costs the same and gives up whatever the newer version improved. Do instead: Decide the pin on behaviour alone, and re-test the newer version on your own evaluation set. - Carrying an old prompt forward across an Opus upgrade. Why it hurts: Prompts written for an older version often over-steer, and every extra token bills at $5 per million. Do instead: Re-test whether the extra steering is still needed, then trim what a newer version handles unprompted. - Running the whole agent loop on Opus because the reasoning step needs it. Why it hurts: Routing and formatting steps bill at $5 and $25 per million to do work a small model does identically. Do instead: Split the loop by step type and price each. This is usually the largest single saving on an agent. ## Self-check - List which Opus version each service pins, and confirm anyone can explain why. - Check whether the pin was ever justified as a cost decision. If so, that reasoning was wrong. - Compare the system prompt on your oldest pin against your newest. Price the difference at $5 per million. - Count what share of your Opus calls are reasoning steps versus mechanical ones. - Price the cache-write rate on your traffic. Opus cache writes bill at $6.25 per million, above the input rate. ## Cache writes above the input rate, and what that means (illustrative) An Opus 4.8 workload sending a 6,000-token system prompt on every call, 200,000 calls a month. Rates from the price book: $5.00 input, $25.00 output, $0.50 cached read, and a five-minute cache write at $6.25 per million, derived at 1.25 times input. No cache, prompt only: 200,000 x 6,000 = 1,200M tokens x $5.00 per million = $6,000 Cached read, prompt only: 1,200M x $0.50 per million = $600, a saving of $5,400 One cache write costs 6,000 tokens x $6.25 per million = $0.0375, against $0.03 for an uncached call The write replaces an uncached call, so its extra cost is $0.0375 - $0.03 = $0.0075 Each later read saves $0.027, so break-even = $0.0075 / $0.027 = 0.28 reads Rebuild the cache on every call and you pay $7,500, which is 25% worse than never caching Caching takes $5,400 a month off this prompt and clears break-even on the first read. Only a cache rebuilt with no read at all loses, and then by 25%. ## Cost figures Every figure carries its confidence and its source. No figure on this site is provider-reported. - $5.00 / $25.00 per million — Claude Opus 4.5, 4.6, 4.7, 4.8 and Opus 5 input and output rates, identical across all five [calculated] Source: Culpa price book rows for anthropic/claude-opus-4-5 through 4-8 and claude-opus-5, all $0.005 and $0.025 per 1k, verified against Anthropic pricing on 2026-08-01. - $6.25 per million — Opus five-minute cache write rate, above the input rate [calculated] Source: $0.005 per 1k input x 1.25, the published Anthropic cache-write multiplier, mirrored from the ledger's own derivation in migration 0020. ## FAQ Q: Is Claude Opus 4.8 more expensive than Opus 4.5? A: No. Opus 4.5, 4.6, 4.7, 4.8 and the newer Opus 5 all bill $5.00 per million input and $25.00 per million output. Choosing between them is a behaviour decision, never a cost one. Q: What does an Opus cache write cost? A: $6.25 per million for the five-minute window and $10.00 for the one-hour window, derived at 1.25 and 2 times the $5.00 input rate. Both sit above the input rate, so a cache you rebuild too often costs more than not caching. Q: Should I run a whole agent on Opus? A: Rarely. Planning and synthesis benefit from it. Tool selection, routing and formatting usually run identically on a model costing a fifth as much, and splitting the loop by step type is generally the biggest saving available. ## Sources - Anthropic pricing: https://platform.claude.com/docs/en/docs/about-claude/pricing Run the free Cost Leak Scan: https://app.getculpa.com/scan?source=pseo&slug=claude-opus-4-8-pricing&cluster=model_pricing Machine-readable index of every guide: https://getculpa.com/api/pages Human-readable index of every guide: https://getculpa.com/guides Site overview: https://app.getculpa.com/llms.txt Privacy: Culpa runs on your infrastructure. Your prompts and responses never leave it. Culpa counts calls to run your plan, and it fails open, so if it ever breaks your app keeps running.