---
title: Claude Sonnet 4.5
url: https://platform.claude.com/docs/it/models/sonnet-4-5/overview
description: "Riferimento per Claude Sonnet 4.5: stato del ciclo di vita, ID del modello su ogni piattaforma, finestra di contesto, limiti di output, prezzi e risorse per la migrazione. Claude Sonnet 4.5 è un modello deprecato; Claude Sonnet 5.5 è l'attuale modello Sonnet."
---
**Deprecated.** Released September 29, 2025.
Claude Sonnet 4.5 is deprecated: it is still functional but no longer recommended, and retires on November 30, 2026. Recommended replacement: Claude Sonnet 5.5. [See Claude Sonnet 5.5](https://platform.claude.com/docs/it/models/sonnet-5-5/overview) · [Migrate to Claude Sonnet 5.5](https://platform.claude.com/docs/it/models/sonnet-5-5/migration-guide#migrating-from-sonnet-45)
Model ID: `claude-sonnet-4-5-20250929`
Context window: 200K tokens · Max output: 64K tokens · Input pricing: $3 / MTok · Output pricing: $15 / MTok
[Announcement](https://www.anthropic.com/news/claude-sonnet-4-5)
## Come si confronta con la lineup attuale
| Model | Context | Max output | Price / MTok | Thinking | Default effort | Knowledge cutoff |
| :---------------------------------------------------------------------------------- | :------ | :--------- | :----------------- | :------------------- | :------------- | :--------------- |
| [Claude Fable 5.1](https://platform.claude.com/docs/it/models/fable-5-1/overview) | 1M | 128K | $10 / $50 | Adaptive (always on) | `high` | Jun 2026 |
| [Claude Opus 5.5](https://platform.claude.com/docs/it/models/opus-5-5/overview) | 1M | 128K | $4 / $20 | Adaptive (always on) | `medium` | Jun 2026 |
| [Claude Sonnet 5.5](https://platform.claude.com/docs/it/models/sonnet-5-5/overview) | 1M | 128K | $2 / $10 | Adaptive | `high` | Jun 2026 |
| **Claude Sonnet 4.5** (this model) | 200K | 64K | $3 / $15 | Extended | — | Jan 2025 |
| [Claude Haiku 5.5](https://platform.claude.com/docs/it/models/haiku-5-5/overview) | 1M | 128K | From $0.10 / $0.50 | Adaptive | `medium` | Jun 2026 |
* **Context:** 1M tokens is roughly 555k words or 2.5M Unicode characters on the current tokenizer (introduced with Claude Opus 4.7); models before it fit about 750k words in 1M tokens. 200k tokens is roughly 150k words.
* **Max output:** Synchronous Messages API limit. On the Message Batches API, Claude Opus 5.5, Claude Opus 5, Claude Sonnet 5.5, Claude Sonnet 5, Claude Haiku 5.5, Claude Opus 4.8, Claude Opus 4.7, Claude Opus 4.6, and Claude Sonnet 4.6 support up to 300k output tokens with the output-300k-2026-03-24 beta header.
* **Price / MTok:** Input / output, base price per million tokens. Batch API requests are 50% off; prompt caching reads cost 10% of the base input price (2.5% on Claude Fable 5.1 and Claude Mythos 5.1, 5% on Claude Opus 5.5 and Claude Sonnet 5.5). See Pricing for the full list.
* **Thinking:** Adaptive thinking lets the model decide how much to think, steered by effort. Extended thinking is the manual budget\_tokens mode on earlier models.
* **Default effort:** The effort parameter’s default on the Claude API. Models without a value don’t support the parameter.
* **Knowledge cutoff:** Reliable knowledge cutoff: the date through which the model’s knowledge is most extensive and reliable.
## Specifiche
### Model IDs
| Platform | Model ID |
| :-------------------------------------------------------------------------------------------------------------------- | :------------------------------------------ |
| Claude API | `claude-sonnet-4-5-20250929` |
| Claude API alias | `claude-sonnet-4-5` |
| [Amazon Bedrock (InvokeModel)](https://platform.claude.com/docs/it/build-with-claude/claude-on-amazon-bedrock-legacy) | `anthropic.claude-sonnet-4-5-20250929-v1:0` |
| [Google Cloud](https://platform.claude.com/docs/it/build-with-claude/claude-on-vertex-ai) | `claude-sonnet-4-5@20250929` |
| [Microsoft Foundry](https://platform.claude.com/docs/it/build-with-claude/claude-in-microsoft-foundry) | `claude-sonnet-4-5` |
| [Claude Platform on AWS](https://platform.claude.com/docs/it/build-with-claude/claude-platform-on-aws) | `claude-sonnet-4-5` |
### Pricing
| Feature | Value |
| :------------------------------------------------------------------------------------- | :------------------------------- |
| Input | $3 / MTok |
| Output | $15 / MTok |
| [5m cache write](https://platform.claude.com/docs/it/build-with-claude/prompt-caching) | $3.75 / MTok |
| [1h cache write](https://platform.claude.com/docs/it/build-with-claude/prompt-caching) | $6 / MTok |
| [Cache read](https://platform.claude.com/docs/it/build-with-claude/prompt-caching) | $0.30 / MTok |
| [Batch API](https://platform.claude.com/docs/it/build-with-claude/batch-processing) | 50% discount on input and output |
[Full price list](https://platform.claude.com/docs/it/about-claude/pricing)
### Capabilities
| Feature | Value |
| :-------------------------------------------------------------------------------------- | :--------------------- |
| [Context window](https://platform.claude.com/docs/it/build-with-claude/context-windows) | 200K tokens |
| Max output | 64K tokens |
| [Thinking](https://platform.claude.com/docs/it/build-with-claude/thinking) | Extended |
| [Default effort](https://platform.claude.com/docs/it/build-with-claude/effort) | Not supported |
| Input → output | Text and images → text |
| Reliable knowledge cutoff | Jan 2025 |
| Training data cutoff | Jul 2025 |
### Availability
| Feature | Value |
| :---------------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [Status](https://platform.claude.com/docs/it/about-claude/model-deprecations) | Deprecated |
| Released | September 29, 2025 |
| Deprecated | September 30, 2026 |
| Retires | November 30, 2026 |
| Platforms | Claude API, [Amazon Bedrock (InvokeModel)](https://platform.claude.com/docs/it/build-with-claude/claude-on-amazon-bedrock-legacy), [Google Cloud](https://platform.claude.com/docs/it/build-with-claude/claude-on-vertex-ai), [Microsoft Foundry](https://platform.claude.com/docs/it/build-with-claude/claude-in-microsoft-foundry), [Claude Platform on AWS](https://platform.claude.com/docs/it/build-with-claude/claude-platform-on-aws) |
## Risorse
Cosa cambia passando da Claude Sonnet 4.5 e dai modelli Sonnet precedenti a Claude Sonnet 5.5.
L'attuale modello Sonnet: panoramica, specifiche e risorse.
## Riferimento
Il prompt di sistema che Claude Sonnet 4.5 utilizza su claude.ai e nelle app Claude.
Valutazioni di sicurezza e decisioni di deployment per Claude Sonnet 4.5.
Listino prezzi completo, inclusi sconti batch e tariffe per la cache dei prompt.
Come funzionano gli ID dei modelli, gli alias e gli snapshot fissati.
Stato del ciclo di vita e impegni di ritiro per ogni modello Claude.
Claude Sonnet 4.5 utilizza l'integrazione InvokeModel di Bedrock e gli ID dei modelli in stile Bedrock.