diff --git a/Cargo.lock b/Cargo.lock
index d2bb106..6272896 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1182,6 +1182,12 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "urlencoding"
+version = "2.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "daf8dba3b7eb870caf1ddeed7bc9d2a049f3cfdfae7cb521b087cc33ae4c49da"
+
 [[package]]
 name = "utf-8"
 version = "0.7.6"
@@ -1289,6 +1295,8 @@ dependencies = [
  "tokio-tungstenite",
  "tracing",
  "tracing-subscriber",
+ "url",
+ "urlencoding",
 ]
 
 [[package]]
diff --git a/Cargo.toml b/Cargo.toml
index 68b2051..0112038 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,3 +11,5 @@ tracing-subscriber = { version = "0.3", features = ["fmt"] }
 clap = { version = "4", features = ["derive"] }
 futures-util = "0.3"
 chrono = "0.4"
+urlencoding = "2"
+url = "2"
diff --git a/src/main.rs b/src/main.rs
index 0d3c8c1..36c37ae 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,6 +3,7 @@ use std::path::PathBuf;
 
 use chrono::Local;
 use clap::Parser;
+use url::Url;
 use futures_util::StreamExt;
 use tokio::task::JoinSet;
 use tokio_tungstenite::{
@@ -30,6 +31,10 @@ struct Args {
     /// Enable debug logging (shows request/response headers)
     #[arg(long)]
     debug: bool,
+
+    /// Query string parameters to add to all URLs (pre-encoded, e.g., "name=First%20Last&key=value")
+    #[arg(short = 'q', long = "query-string-all")]
+    query_string_all: Option<String>,
 }
 
 #[tokio::main]
@@ -53,9 +58,46 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     fs::create_dir_all(&session_dir)?;
     info!("Created session directory: {}", session_dir.display());
 
+    // Process URLs and add query string parameters if specified
+    let mut processed_urls = Vec::new();
+    for url_str in &args.urls {
+        let mut url = Url::parse(url_str)?;
+
+        if let Some(ref extra_params) = args.query_string_all {
+            // Parse existing query string and extra params
+            let existing: Vec<(String, String)> = url
+                .query_pairs()
+                .map(|(k, v)| (k.into_owned(), v.into_owned()))
+                .collect();
+
+            let extra: Vec<(&str, &str)> = extra_params
+                .split('&')
+                .filter(|s| !s.is_empty())
+                .filter_map(|pair| pair.split_once('='))
+                .collect();
+
+            // Rebuild query string with existing + extra params
+            {
+                let mut query_pairs = url.query_pairs_mut();
+                query_pairs.clear();
+                for (k, v) in &existing {
+                    query_pairs.append_pair(k, v);
+                }
+                for (k, v) in &extra {
+                    // Decode first since append_pair will re-encode
+                    let k_decoded = urlencoding::decode(k).unwrap_or_else(|_| (*k).into());
+                    let v_decoded = urlencoding::decode(v).unwrap_or_else(|_| (*v).into());
+                    query_pairs.append_pair(&k_decoded, &v_decoded);
+                }
+            }
+        }
+
+        processed_urls.push(url.to_string());
+    }
+
     // Connect to all URLs simultaneously
     let mut connect_futures = Vec::new();
-    for (idx, url) in args.urls.iter().enumerate() {
+    for (idx, url) in processed_urls.iter().enumerate() {
         let letter = (b'A' + idx as u8) as char;
         let bearer_token = args.bearer_token.clone();
         let url = url.clone();