Claude Sonnet 4.5
by Anthropic
Anthropic’s coding-first Claude model for agents and developers.
Score
Score
Our verdict
Excellent coding model with clear usage‑based API pricing, strong agent tooling, and broad availability. 200K context may be limiting vs newer Sonnet models.
Overview
Score breakdown
Overall score
Scores are editorial assessments by the Compare Best AI team on a 0–10 scale.
Expert review
CBAI Editorial Team
Compare Best AI · Editorial Team
Claude Sonnet 4.5 remains a compelling developer model thanks to strong coding and agentic performance, straightforward API pricing ($3/$15 per MTok), and support for cost optimizers like Batch and prompt caching. It’s broadly available: first‑party via the Claude API and on partner clouds, and in the Claude apps for chat and coding.
How we tested
Tasks evaluated
- ·Verified Sonnet 4.5 API pricing, batch, and prompt caching on Anthropic docs.
- ·Checked seat plan names and monthly/annual rates on claude.com/pricing.
- ·Confirmed Sonnet 4.5 GA context window and availability on AWS and Google Cloud.
- ·Validated official announcement details (model name, positioning, drop‑in replacement).
Method
Document-based verification from Anthropic’s official pricing, product pages, and partner cloud model cards; no hands-on testing performed.
Reviewer
CBAI Editorial Team
Plans & pricing
API — Standard (Sonnet 4.5)
/MTok input; $15/MTok output
On‑demand API usage
- Prompt caching: 5m writes $3.75/MTok; 1h writes $6/MTok; cache hits/refreshes $0.30/MTok.
- Model ID: claude-sonnet-4-5.
- First‑party Claude API; also available via partner clouds.
API — Batch (Sonnet 4.5)
/MTok input; $7.50/MTok output
Asynchronous large jobs at lower cost
- Lower-cost batch processing for Sonnet 4.5.
- Subject to Batch API constraints; prompt caching priced separately.
Free
Trying Claude apps
- Web, iOS, Android, desktop access
- Web search, memory, projects, files with code execution (limited)
- Connectors (Slack, Google Workspace)
Pro
Individual power users
- $17/mo billed annually ($200 upfront)
- Includes Claude Code, Cowork, Design, Science
- Access to Research and more Claude models
- Claude for Microsoft 365 access
Max
Heavy individual usage
- Higher output limits than Pro (5x or 20x)
- Early access to advanced features
- Priority access at high traffic times
Team — Standard seat
Small to midsize teams
- $20/seat/mo if billed annually
- More usage than Pro
- Central billing & admin, SSO, connectors
- Includes Code, Cowork, Design, Science
Team — Premium seat
Teams needing more usage headroom
- $100/seat/mo if billed annually
- ~5x more usage than Standard seats
- All Team features included
Enterprise (self‑serve/sales‑assisted)
/seat + API usage rates
Large orgs at scale
- Admins set spend limits; role‑based access
- SSO, SCIM, audit logs, Compliance API
- HIPAA‑ready offering; IP allowlisting; custom data retention
Pricing may vary by region. Always verify on the vendor's website.
Feature comparison
- Model available via Claude API as “claude-sonnet-4-5”.
- Usage‑based API pricing: $3/MTok input and $15/MTok output (standard).
- Batch API supported at ~50% of standard rates for Sonnet 4.5.
- Prompt caching supported with 5‑minute and 1‑hour TTL pricing tiers.
- Available in Claude apps and Claude Code; drop‑in replacement for Sonnet 4 per Anthropic.
- GA context window of 200K tokens for Sonnet 4.5 on supported platforms.
- Available on partner clouds (Amazon Bedrock, Google Cloud) in addition to first‑party Claude API.
- Agent SDK and new context/memory tools announced alongside Sonnet 4.5 release.
Is it right for you?
Good fit for
Coding and software engineering
Optimized for code generation, debugging, and complex multi‑step dev tasks.
Agentic workflows
Build tool‑using agents with prompt caching and batch processing to manage cost and latency.
Enterprise rollouts
Seat plans with SSO/SCIM and compliance controls; API usage rates for scalable workloads.
Less suited for
Workloads needing 1M‑token context on Sonnet
Use Sonnet 4.6/5 for 1M context; Sonnet 4.5 GA is 200K.
Ultra‑low‑cost inference
If cost is primary, Haiku 4.5 offers lower per‑token rates.
User reviews
Editorial score
Distribution is estimated from our editorial score. Verified user reviews coming soon.
Use cases
Typical ways teams rely on this tool — from everyday tasks to specialized workflows.
- Coding assistant and refactoring at scale
- Building autonomous or tool‑using agents for software tasks
- Running long multi‑step workflows with code execution in apps
- Batch processing of large code or document jobs with discounted API rates
Integrations
Reported connectors
Apps and services commonly connected out of the box or via official connectors.
- Amazon Bedrock
- Google Cloud (Gemini Enterprise Agent Platform)
- Microsoft Foundry (Azure)
- Slack
- Google Workspace
- Microsoft 365
- Microsoft Outlook
- Claude for Chrome
Privacy & compliance
Security & data practices
Highlights we track from the vendor's documentation. Always confirm current terms, subprocessors, and regional policies on their official site.
- Enterprise plan lists SSO
- SCIM
- audit logs
- Compliance API
- IP allowlisting
- custom data retention
- and a HIPAA‑ready offering.
Details
Category
Price
- $3/MTok input
- $15/MTok output (API)
Free version
Best for
Sonnet 4.5 suits IDE/agent workflows, code generation and refactoring, data/tool use, and long multi‑step tasks. Org buyers can combine seat plans for the apps with usage‑rated API access.
Frequently asked questions
Claude Sonnet 4.5
Developer
Ready to get started?
Visit the Claude Sonnet 4.5 website to explore plans and start your free trial.
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