diff --git a/_locales/en/messages.json b/_locales/en/messages.json
index 84e0f98d..1dfe4efc 100644
--- a/_locales/en/messages.json
+++ b/_locales/en/messages.json
@@ -634,5 +634,13 @@
   "prefs_OptionText_placeholders_use_default_value_info": {
     "message": "If checked, the placeholders will be filled with the default values when no value is provided. Otherwise, the placeholders will be kept in place.",
     "description": ""
+  },
+  "prefs_OptionText_max_prompt_length" : {
+    "message": "Max prompt length",
+    "description": ""
+  },
+  "prefs_OptionText_max_prompt_length_Info" : {
+    "message": "This is the maximum number of characters that can be used in a prompt. Otherwise, an error message will be displayed. The value is not editable for the ChatGPT Web Interface.",
+    "description": ""
   }
 }
\ No newline at end of file
diff --git a/mzta-background.js b/mzta-background.js
index b91d2ee5..81ad08d7 100644
--- a/mzta-background.js
+++ b/mzta-background.js
@@ -245,7 +245,7 @@ async function openChatGPT(promptText, action, curr_tabId, prompt_name = '', do_
     prefs = checkScreenDimensions(prefs);
     //console.log(">>>>>>>>>>>>>>>> prefs: " + JSON.stringify(prefs));
     taLog.log("[ThunderAI] Prompt length: " + promptText.length);
-    if(promptText.length > 30000 ){
+    if(promptText.length > prefs.max_prompt_length){
         // Prompt too long for ChatGPT
         browser.tabs.sendMessage(curr_tabId, { command: "promptTooLong" });
         return;
diff --git a/options/mzta-options-default.js b/options/mzta-options-default.js
index f3b41862..1e5d97a6 100644
--- a/options/mzta-options-default.js
+++ b/options/mzta-options-default.js
@@ -33,4 +33,5 @@ export const prefs_default = {
     dynamic_menu_force_enter: false,
     dynamic_menu_order_alphabet: true,
     placeholders_use_default_value: false,
+    max_prompt_length: 30000,   // max string length for prompt
 }
\ No newline at end of file
diff --git a/options/mzta-options.html b/options/mzta-options.html
index 70ed66ac..adcbc429 100644
--- a/options/mzta-options.html
+++ b/options/mzta-options.html
@@ -220,6 +220,15 @@
           </label>
         </td>
       </tr>
+      <tr>
+        <td><span>__MSG_prefs_OptionText_max_prompt_length__</span></td>
+        <td>
+          <label>
+            <input type="number" id="max_prompt_length" name="max_prompt_length" class="option-input" />
+            <br>__MSG_prefs_OptionText_max_prompt_length_Info__
+          </label>
+        </td>
+      </tr>
       <tr>
         <td style="width:20em"><label>
           <span>__MSG_Debug__</span>
diff --git a/options/mzta-options.js b/options/mzta-options.js
index dcdc7d9b..a944b77a 100644
--- a/options/mzta-options.js
+++ b/options/mzta-options.js
@@ -93,6 +93,7 @@ async function restoreOptions() {
 }
 
 function showConnectionOptions() {
+  disable_MaxPromptLength();
   let chatgpt_web_display = 'table-row';
   let chatgpt_api_display = 'none';
   let ollama_api_display = 'none';
@@ -203,6 +204,12 @@ function warn_OpenAIComp_HostEmpty() {
   }
 }
 
+function disable_MaxPromptLength(){
+  let maxPromptLength = document.getElementById('max_prompt_length');
+  let conntype_select = document.getElementById("connection_type");
+  maxPromptLength.disabled = (conntype_select.value === "chatgpt_web");
+}
+
 document.addEventListener('DOMContentLoaded', async () => {
   await restoreOptions();
   i18n.updateDocument();
@@ -358,6 +365,7 @@ select_openai_comp_model.addEventListener("change", warn_OpenAIComp_HostEmpty);
   warn_ChatGPT_APIKeyEmpty();
   warn_Ollama_HostEmpty();
   warn_OpenAIComp_HostEmpty();
+  disable_MaxPromptLength();
 
   const passwordField_chatgpt_api_key = document.getElementById('chatgpt_api_key');
   const toggleIcon_chatgpt_api_key = document.getElementById('toggle_chatgpt_api_key');