Anthropic prices Claude Opus 4.5 at $5/1M input and $25/1M output tokens, much cheaper than Opus 4.1 at $15/$75 but still pricier than GPT-5.1 and Gemini 3 Pro
Opus 4.5 was responsible for most of the work across 20 commits, 39 files changed, 2,022 additions and 1,173 deletions in a two day period. … Forums: r/BetterOffline : Claude Opus 4.5, and why evaluating new LLMs is increasingly difficult
This price reset puts the Opus tier into a sharper cost-performance contest. It also precedes later signs that Anthropic would vary the offer by operating mode, including a faster, substantially more expensive Opus 4.6 mode.
First-order effects
Developers using Opus-class workloads can access Opus 4.5 at one-third of Opus 4.1’s listed input and output token rates, lowering the immediate API bill for comparable token use.
Anthropic narrows the price premium of its flagship line, though GPT-5.1 and Gemini 3 Pro retain a listed-price advantage over Opus 4.5.
Second-order effects
The cut increases pressure on competing frontier-model providers to defend price-performance, especially for coding and agentic workloads where output-token costs can dominate usage bills.
Buyers will have more reason to compare models on completed work rather than token rates alone; the reported two-day, multi-commit use of Opus 4.5 illustrates why coding-task performance comparisons matter alongside list prices.
Third-order effects
If flagship-model price reductions persist, model vendors will compete less on a fixed premium tier and more on differentiated combinations of quality, speed, and usage pricing.
Token prices will become a weaker standalone buying signal as providers introduce operating-mode choices and model-specific processing changes; effective cost per useful task is likely to become the more durable benchmark.
The trend: Frontier AI providers are compressing flagship inference prices while segmenting their offerings by the performance and speed customers are willing to pay for.
one fact people won't realize immediately about opus 4.5: it's remarkably token-efficient. all-in it's often *cheaper* than sonnet 4.5 and other models for cost-per-task-success. glad sourcegraph is seeing this early in Amp! we find that opus 4.5 with medium effort is pareto [ima…
We need a new way to express AI costs... $/token doesn't make much sense anymore. Maybe a benchmark that tries to give a sense of the cost to run an average workload?
Opus is worth it, and maybe cheaper all-in than Sonnet? Early rough non-representative numbers, for our own internal @AmpCode usage (avg cost $ per thread): - Sonnet 4.5: $1.83 - Opus 4.5: $1.30 (earlier checkpoint last week was $1.55) - Gemini 3 Pro: $1.21
They're burying a lot here. There's a 66% price cut from Opus 4.1 to $5/$25, it uses fewer tokens to solve problems, upgrades to Claude Code in the app, no more length limits on conversations, no more Opus-specific plan caps...
It's also dramatically more efficient. On SWE-bench Verified at medium effort, Opus 4.5 beats Sonnet 4.5 while using 76% fewer output tokens. The new effort parameter lets you trade off intelligence for cost/latency with a single dial. [image]
Updated my post with this section about their improved protection against prompt injection attacks - definitely better, but the problem is that if an attacker gets 10 tries they'll still succeed 1/3rd of the time! https://simonwillison.net/... [image]
Opus models have always been “the real SOTA” but have been cost prohibitive in the past. Claude Opus 4.5 is now at a price point where it can be your go-to model for most tasks. It's the clear winner and exhibits the best frontier task planning and tool calling we've seen yet.