diff --git a/src/main.rs b/src/main.rs
index 30d0384..9c25a15 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -41,6 +41,10 @@ struct Args {
     /// jq expression(s) to evaluate on JSON text messages for logging (can be specified multiple times)
     #[arg(short = 'j', long = "jaq")]
     jaq: Vec<String>,
+
+    /// Normalize JSON messages: save as .json with pretty-printing and sorted keys (for easier diffing)
+    #[arg(short = 'n', long = "json-normalize")]
+    json_normalize: bool,
 }
 
 #[tokio::main]
@@ -263,6 +267,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     for (letter, url, ws_stream) in connections {
         let session_dir = session_dir.clone();
         let jaq_filters = jaq_filters.clone();
+        let json_normalize = args.json_normalize;
 
         join_set.spawn(async move {
             let (_, mut read) = ws_stream.split();
@@ -336,10 +341,30 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
                                     }
                                 }
 
-                                // Always write full message to file
-                                let filename =
-                                    session_dir.join(format!("{}{}.txt", letter, seq_num));
-                                if let Err(e) = fs::write(&filename, &text) {
+                                // Write message to file
+                                let (filename, content) = if json_normalize {
+                                    if let Ok(json_val) =
+                                        serde_json::from_str::<serde_json::Value>(&text)
+                                    {
+                                        let pretty =
+                                            serde_json::to_string_pretty(&json_val).unwrap_or(text.clone());
+                                        (
+                                            session_dir.join(format!("{}{}.json", letter, seq_num)),
+                                            pretty,
+                                        )
+                                    } else {
+                                        (
+                                            session_dir.join(format!("{}{}.txt", letter, seq_num)),
+                                            text.clone(),
+                                        )
+                                    }
+                                } else {
+                                    (
+                                        session_dir.join(format!("{}{}.txt", letter, seq_num)),
+                                        text.clone(),
+                                    )
+                                };
+                                if let Err(e) = fs::write(&filename, content) {
                                     error!("[{}] Failed to write {:?}: {}", letter, filename, e);
                                 }
                             }