Claude Sonnet 4.5
Claude Sonnet 4.5Alternatives?
CheaperGemini 4 Argonhighwins 59%-33%*$1.99Synchronous output stops at 65,536+2
BetterGPT-5.6 Solxhighwins 52%+33%$1.18
OpenKimi K3maxsamesame$2.00Sampling parameters are fixed+3CheaperGemini 3.8 Flashhighwins 55%-75%*$1.24Sampling parameters are ignored+1CheaperGemini 3.1 Pro Previewunstatedwins 54%-25%$2 / $12Cannot use both thinking controlsGemini 4 Argonhighwins 59%-33%*$1.99Synchronous output stops at 65,536+2Gemini 3.8 Flashhighwins 55%-75%*$1.24Sampling parameters are ignored+1Gemini 3.1 Pro Previewunstatedwins 54%-25%$2 / $12Cannot use both thinking controlsGemini 3.6 Flashhighwins 52%-75%*$1.60
Muse Sparkunstatedsame-67%$1.25 / $4.25Only n=1 · Meta / Chat Completions+1GPT-5.6 Solxhighwins 52%+33%$1.18Gemini 3.8 Flashhighwins 55%-75%*$1.24Sampling parameters are ignored+1Gemini 3.6 Flashhighwins 52%-75%*$1.60Claude Opus 5.5highwins 59%+33%$1.82No forced tool use+5Gemini 4 Argonhighwins 59%-33%*$1.99Synchronous output stops at 65,536+2Kimi K3maxOpensamesame$2.00Sampling parameters are fixed+3
GLM 5.2maxOpensame-64%$1.47No image inputGLM 5.3maxOpensame-64%$2.01No image input+4GLM 5unstatedOpensame-74%$1 / $3.20Context: 1M → 203K+1GLM 5.1unstatedOpensame-64%$1.40 / $4.40Context: 1M → 203K+1Claude Opus 5.5highwins 59%—$1.82No forced tool use+5Claude Fable 5highwins 57%—$10 / $50Claude Opus 4.6highwins 57%—$5 / $25Claude Opus 4.7highwins 55%—$5 / $25Claude Fable 5.1maxwins 54%—$7.63Replace forced tool_choice+5Claude Opus 5maxwins 52%—$5.86Claude Opus 4.8highwins 52%—$5 / $25Claude Opus 4.5highwins 52%—$5 / $25Context: 1M → 200KAll Anthropic models →History
7 versionsBenchmarks
in Writing & LanguageFAQ
How much does Claude Sonnet 4.5 cost?›
$3 per 1M input tokens and $15 per 1M output tokens; cached input $0.30 per 1M.
Is Claude Sonnet 4.5 free to use?›
There is no free API; the cheapest paid price is $3 per 1M input tokens.
How good is Claude Sonnet 4.5, and what is it best at?›
#220 of 334 in Chat & Knowledge, #75 of 132 in Coding, #70 of 133 in Agents & Tool Use, #21 of 195 in Writing & Language, #80 of 124 in Vision & Documents.
Is Claude Sonnet 4.5 better than Gemini 3 Flash Preview?›
On Arena Text · creative writing, Claude Sonnet 4.5 scores 1,454 vs 1,457 — about the same.
How can I use Claude Sonnet 4.5?›
Through the API of Amazon Bedrock, Anthropic, Azure, Claude Platform on AWS, Google.
What is the context window of Claude Sonnet 4.5?›
1M tokens, with up to 64K output tokens.
When was Claude Sonnet 4.5 released? Is there a newer version?›
Released 2025-09-29. It has been superseded by Claude Sonnet 5.5.
Is Claude Sonnet 4.5 open source?›
No, Claude Sonnet 4.5 is a closed model available through an API. The closest open-weights option here is Kimi K3.
Can Claude Sonnet 4.5 read images?›
It accepts text and images, PDF files as input.
What is Claude Sonnet 4.5?›
Claude Sonnet 4.5 is a closed language model from Anthropic, released Sep 2025.
What are the best alternatives to Claude Sonnet 4.5?›
Gemini 4 Argon (cheaper), GPT-5.6 Sol (better), Kimi K3 (open weights).