diff --git a/README.md b/README.md
index 6c30587c5..d750ae543 100644
--- a/README.md
+++ b/README.md
@@ -6,8 +6,8 @@
 Aider lets you pair program with LLMs,
 to edit code in your local git repository.
 Start a new project or work with an existing git repo.
-Aider works best with GPT-4o and Claude 3 Opus
-and can [connect to almost any LLM](https://aider.chat/docs/llms.html).
+Aider can [connect to almost any LLM](https://aider.chat/docs/llms.html).
+and works best with GPT-4o, Claude 3.5 Sonnet and Claude 3 Opus.
 
 <p align="center">
   <img
diff --git a/aider/args.py b/aider/args.py
index 98b612905..b0da24dad 100644
--- a/aider/args.py
+++ b/aider/args.py
@@ -7,7 +7,11 @@ import sys
 import configargparse
 
 from aider import __version__, models
-from aider.args_formatter import MarkdownHelpFormatter, YamlHelpFormatter, DotEnvFormatter
+from aider.args_formatter import (
+    DotEnvFormatter,
+    MarkdownHelpFormatter,
+    YamlHelpFormatter,
+)
 
 from .dump import dump  # noqa: F401
 
@@ -43,10 +47,7 @@ def get_parser(default_config_files, git_root):
         help="Log the conversation with the LLM to this file (for example, .aider.llm.history)",
     )
     group.add_argument(
-        "files",
-        metavar="FILE",
-        nargs="*",
-        help="files to edit with an LLM (optional)"
+        "files", metavar="FILE", nargs="*", help="files to edit with an LLM (optional)"
     )
     group.add_argument(
         "--openai-api-key",
@@ -75,7 +76,7 @@ def get_parser(default_config_files, git_root):
         const=opus_model,
         help=f"Use {opus_model} model for the main chat",
     )
-    sonnet_model = "claude-3-sonnet-20240229"
+    sonnet_model = "claude-3-5-sonnet-20240620"
     group.add_argument(
         "--sonnet",
         action="store_const",
@@ -516,6 +517,7 @@ def get_sample_yaml():
     return argparse.ArgumentParser.format_help(parser)
     return parser.format_help()
 
+
 def get_sample_dotenv():
     os.environ["COLUMNS"] = "120"
     sys.argv = ["aider"]
@@ -529,6 +531,7 @@ def get_sample_dotenv():
     return argparse.ArgumentParser.format_help(parser)
     return parser.format_help()
 
+
 def main():
     arg = sys.argv[1] if len(sys.argv[1:]) else None
 
@@ -540,7 +543,6 @@ def main():
         print(get_sample_yaml())
 
 
-
 if __name__ == "__main__":
     status = main()
     sys.exit(status)
diff --git a/website/assets/sample.aider.conf.yml b/website/assets/sample.aider.conf.yml
index 896cda62a..ed48f18e1 100644
--- a/website/assets/sample.aider.conf.yml
+++ b/website/assets/sample.aider.conf.yml
@@ -28,7 +28,7 @@
 ## Use claude-3-opus-20240229 model for the main chat
 #opus: false
 
-## Use claude-3-sonnet-20240229 model for the main chat
+## Use claude-3-5-sonnet-20240620 model for the main chat
 #sonnet: false
 
 ## Use gpt-4-0613 model for the main chat
diff --git a/website/assets/sample.env b/website/assets/sample.env
index 02251c4b9..551d76de3 100644
--- a/website/assets/sample.env
+++ b/website/assets/sample.env
@@ -36,7 +36,7 @@
 ## Use claude-3-opus-20240229 model for the main chat
 #AIDER_OPUS=
 
-## Use claude-3-sonnet-20240229 model for the main chat
+## Use claude-3-5-sonnet-20240620 model for the main chat
 #AIDER_SONNET=
 
 ## Use gpt-4-0613 model for the main chat
diff --git a/website/docs/aider_conf.md b/website/docs/aider_conf.md
index b13208cc7..9e4eed9d3 100644
--- a/website/docs/aider_conf.md
+++ b/website/docs/aider_conf.md
@@ -56,7 +56,7 @@ cog.outl("```")
 ## Use claude-3-opus-20240229 model for the main chat
 #opus: false
 
-## Use claude-3-sonnet-20240229 model for the main chat
+## Use claude-3-5-sonnet-20240620 model for the main chat
 #sonnet: false
 
 ## Use gpt-4-0613 model for the main chat
diff --git a/website/docs/dotenv.md b/website/docs/dotenv.md
index fd32e1a13..b7c942923 100644
--- a/website/docs/dotenv.md
+++ b/website/docs/dotenv.md
@@ -69,7 +69,7 @@ cog.outl("```")
 ## Use claude-3-opus-20240229 model for the main chat
 #AIDER_OPUS=
 
-## Use claude-3-sonnet-20240229 model for the main chat
+## Use claude-3-5-sonnet-20240620 model for the main chat
 #AIDER_SONNET=
 
 ## Use gpt-4-0613 model for the main chat
diff --git a/website/docs/llms.md b/website/docs/llms.md
index aecb49f27..76862b2e6 100644
--- a/website/docs/llms.md
+++ b/website/docs/llms.md
@@ -14,8 +14,8 @@ description: Aider can connect to most LLMs for AI pair programming.
 ## Best models
 {: .no_toc }
 
-**Aider works best with [GPT-4o](/docs/llms/openai.html) and
-[Claude 3 Opus](/docs/llms/anthropic.html),**
+**Aider works best with [GPT-4o](/docs/llms/openai.html),
+[Claude 3.5 Sonnet and Claude 3 Opus](/docs/llms/anthropic.html),**
 as they are the very best models for editing code.
 
 ## Free models
diff --git a/website/docs/llms/anthropic.md b/website/docs/llms/anthropic.md
index c2d2ff78f..027feef44 100644
--- a/website/docs/llms/anthropic.md
+++ b/website/docs/llms/anthropic.md
@@ -22,7 +22,7 @@ setx   ANTHROPIC_API_KEY <key> # Windows
 # Claude 3 Opus
 aider --opus
 
-# Claude 3 Sonnet
+# Claude 3.5 Sonnet
 aider --sonnet
 
 # List models available from Anthropic
diff --git a/website/docs/options.md b/website/docs/options.md
index 300330894..a71d3f00c 100644
--- a/website/docs/options.md
+++ b/website/docs/options.md
@@ -75,7 +75,7 @@ Use claude-3-opus-20240229 model for the main chat
 Environment variable: `AIDER_OPUS`  
 
 ### `--sonnet`
-Use claude-3-sonnet-20240229 model for the main chat  
+Use claude-3-5-sonnet-20240620 model for the main chat  
 Environment variable: `AIDER_SONNET`  
 
 ### `--4`
diff --git a/website/index.md b/website/index.md
index 0a362d291..98a08a5b0 100644
--- a/website/index.md
+++ b/website/index.md
@@ -20,8 +20,8 @@ cog.out(text)
 Aider lets you pair program with LLMs,
 to edit code in your local git repository.
 Start a new project or work with an existing git repo.
-Aider works best with GPT-4o and Claude 3 Opus
-and can [connect to almost any LLM](https://aider.chat/docs/llms.html).
+Aider can [connect to almost any LLM](https://aider.chat/docs/llms.html).
+and works best with GPT-4o, Claude 3.5 Sonnet and Claude 3 Opus.
 
 <p align="center">
   <img