Pricing milestones
| Date | Pricing event | What to cite |
|---|---|---|
| 2023-07-11 | Claude 2 API was offered at the same price as Claude 1.3. | Claude 2 launch |
| 2023-11-21 | Claude 2.1 announced updated pricing to improve cost efficiency across models. | Claude 2.1 launch |
| 2024-06-21 | Claude 3.5 Sonnet launched at $3 input / $15 output per MTok. | Claude 3.5 Sonnet |
| 2025-09-29 | Claude Sonnet 4.5 kept Sonnet 4 pricing at $3/$15 per MTok. | Sonnet 4.5 |
| 2025-11-24 | Claude Opus 4.5 launched at $5/$25 per MTok, resetting the modern Opus rate. | Opus 4.5 |
| 2026-06-30 | Claude Sonnet 5 launched at $2/$10 per MTok, announced as introductory through August 31, 2026. | Sonnet 5 |
| 2026-07-24 | Claude Opus 5 launched at $5/$25 per MTok, the same rate as Opus 4.8, with fast mode at 2x the base price for roughly 2.5x speed. | Opus 5 |
| 2026-09-01 | Claude Fable 5.1 launched at $10/$50 per MTok, with cache reads cut to $0.25 per MTok (2.5% of base input instead of the usual 10%). | Fable/Mythos 5.1 |
| 2026-09-01 | The Sonnet 5 introductory rate became the standard rate. It did not rise to $3/$15 as originally announced. | Pricing docs |
Rate snapshot, September 19, 2026
A dated snapshot for citation, not a live price desk. On September 19, 2026 the pricing docs list Fable 5.1 and Mythos 5.1 at $10/$50 per MTok, Opus 5 and Opus 4.8/4.7/4.6/4.5 at $5/$25, Sonnet 5 at $2/$10, Sonnet 4.6 and 4.5 at $3/$15, and Haiku 4.5 at $1/$5. Cache reads run at 10% of base input on most models and 2.5% on Fable 5.1 and Mythos 5.1; the Batch API discount is 50%.
For current rates, caching math, and cost analysis, go to Claude Reports and the official pricing page. This archive keeps the dated event trail so you can tell when a rate changed and what it replaced.
The September 1, 2026 Sonnet 5 non-increase
When Sonnet 5 launched on June 30, 2026, Anthropic described $2 input / $10 output per MTok as introductory pricing running through August 31, 2026, with a standard rate of $3/$15 to follow. That increase did not happen. As of September 1, 2026 the pricing page carries $2/$10 as the standard Sonnet 5 rate.
The archive records this as its own dated event because the original announcement is still widely quoted. Any page still saying "Sonnet 5 rises to $3/$15 on September 1" is repeating a superseded plan, and any budget model built on that assumption over-forecasts Sonnet 5 spend by 50%.
The real pricing history is context plus tokens
Large context windows changed what one request could contain. Claude 2 publicized 100K tokens, Claude 2.1 moved to 200K, and the Fable 5.1, Opus 5, and Sonnet 5 entries list 1M-token context windows. That makes price history inseparable from context-window history: the same per-token rate can support very different product designs if the model can keep more material in one request.
Caching is the other lever. Cache reads normally bill at 10% of base input, but the Fable 5.1 announcement cut them to 2.5% ($0.25 per MTok), which Anthropic described as roughly 25% savings on typical workloads and up to about 45% on highly agentic ones. A headline rate of $10/$50 therefore says less about real cost in 2026 than it did in 2024.
Tokenizers matter too. The pricing docs say Claude Opus 4.7 and later Opus models, the Fable and Mythos models, and Sonnet 5 use a newer tokenizer that produces approximately 30% more tokens for the same text than Sonnet 4.6 and earlier. That is a pricing-history fact, not only a migration footnote.
Avoid stale pricing quotes
Pricing pages change, and superseded plans outlive them. Launch posts are useful for historical rates, but current budget decisions should cite the live pricing docs. When a page here mentions a rate, it names the source date and links directly to the official Anthropic source.
The two most commonly repeated stale Claude pricing claims as of September 2026 are that Sonnet 5 rose to $3/$15 on September 1 (it did not) and that Opus 4.8 is the current Opus rate card (Opus 5 launched July 24, 2026 at the same $5/$25).
Questions this page answers
What was Claude 3.5 Sonnet priced at launch?
Anthropic stated Claude 3.5 Sonnet cost $3 per million input tokens and $15 per million output tokens at launch.
Did Claude Sonnet 5 pricing increase on September 1, 2026?
No. The $2 input / $10 output per MTok rate was announced as introductory through August 31, 2026 with a planned rise to $3/$15, but the increase did not happen. The pricing docs carry $2/$10 as the standard Sonnet 5 rate.
What does Claude Opus 5 cost?
Opus 5 launched on July 24, 2026 at $5 input / $25 output per MTok, the same rate as Opus 4.8. Its fast mode runs at roughly 2.5x speed for 2x the base price.
Why can the same text cost differently on newer Claude models?
The pricing docs say Sonnet 5 and the newer Opus, Fable, and Mythos models use a newer tokenizer that can produce approximately 30% more tokens for the same text.