diff --git a/src/imgsort.php b/src/imgsort.php
index ccf8e62..1e4346d 100644
--- a/src/imgsort.php
+++ b/src/imgsort.php
@@ -5,7 +5,10 @@
     // All paths require trailing slashes!
     $rootDir = __DIR__ . '/../images/';
     // The URI at which the rootDir will be served
-    $rootPath = 'images/';
+    // Use /images/ for testing
+    // When the app is not served at the root https://example.com/ but at a sublocation like https://example.com/imgsort2/,
+    // you might need to set it to just `images` without the /
+    $rootPath = '/images/';
     // Path of the directory containing all the files to be sorted, relative to $rootDir
     $stagingDirName = '.sort/';
 
@@ -77,27 +80,23 @@
     /**
      * Move a file from staging to the destination directory
      * @param file relative to stagingDir
-     * @param dir  relative to rootDir
+     * @param dest new filename relative to rootDir
      */
-    function moveFile($file, $dir) {
+    function moveFile($file, $dest) {
         global $stagingDir, $rootDir;
         $fullFile = $stagingDir . $file;
-        $fullDir = $rootDir . $dir . "/";
-        $fullDest = $fullDir . basename($fullFile);
+        $fullDest = $rootDir . $dest;
         return saveMove($fullFile, $fullDest);
     }
 
     /**
-     * Move a file from destination directory back to the staging directory
-     * @param dir  relative to rootDir
-     * @param file relative to rootDir/dir
+     * Like movefile, except reversed
      */
-    function undoFile($file, $dir) {
+    function undoFile($file, $dest) {
         global $stagingDir, $rootDir;
-        $fullDir = $rootDir . $dir . "/";
-        $fullFile = $fullDir . $file;
-        $fullDest = $stagingDir . basename($fullFile);
-        return saveMove($fullFile, $fullDest);
+        $fullFile = $stagingDir . $file;
+        $fullDest = $rootDir . $dest;
+        return saveMove($fullDest, $fullFile);
     }
 
 
diff --git a/src/index.html b/src/index.html
index 9b10520..0ec6e23 100644
--- a/src/index.html
+++ b/src/index.html
@@ -22,6 +22,7 @@
 
         <div class="second-box">
             <div id="buttons">
+                <input id="filename" placeholder="filename" type="text" class="filename-input">No file</input>
                 <button onclick="undo()" id="undo-button">Undo</button>
                 <button onclick="skip()" id="skip-button">Skip</button>
                 <span class="move-buttons" id="move-buttons"></span>
diff --git a/src/index.js b/src/index.js
index 8670d64..345edd1 100644
--- a/src/index.js
+++ b/src/index.js
@@ -2,6 +2,9 @@ const imageExtensions = ['gif','jpg','jpeg','png', 'webp'];
 const videoExtensions =['mpg', 'mp2', 'mpeg', 'mpe', 'mpv', 'mp4'];
 const audioExtensions =['mp3', 'ogg', 'wav', 'flac'];
 
+const invalidFileNameCharsRe  =/[^\\/\|:\*\?"<>]/;   // dont allow \/|:*?<>
+const invalidFileNameChars = "\\/|:*?<>";
+
 const mappings = new Map(JSON.parse(localStorage.getItem('mappings')) || []);
 let statusLine = document.getElementById('status');
 // store for when done with sorting TODO display
@@ -203,6 +206,11 @@ function setCurrentFile() {
         currentFile = "";
         statusLine.textContent = "No more files to sort";
     }
+    
+    // set filename in input field
+    const fileNameNoExt = currentFile.replace(/\.[^/.]+$/, "");
+    document.getElementById('filename').value = fileNameNoExt;
+
     renderCurrentFile();
     renderFileList();
 }
@@ -211,15 +219,35 @@ function setCurrentFile() {
 
 async function moveFile(directory) {
     if (!currentFile) {
-        statusLine.innerHTML = "No file to process!";
-        return
+        statusLine.textContent = "No file to process!";
+        return;
     }
-    const response = await fetch(`imgsort.php?action=moveFile&file=${escape(currentFile)}&dest=${directory}`);
+    const userSetFilename = document.getElementById('filename').value;
+    if (!userSetFilename) {
+        statusLine.textContent = "Filename must not be empty";
+        return;
+    }
+    // file names invalid on windows not handled
+    if (invalidFileNameCharsRe.test(userSetFilename)) {
+        statusLine.textContent = `Filename must not contain ${invalidFileNameChars}`;
+        return;
+    }
+
+    // re-add the extension
+    const fileExt = currentFile.split('.').pop();
+    let filename = userSetFilename + '.' + fileExt;
+
+    let newFilePath = directory + '/' + filename;
+    const response = await fetch(`imgsort.php?action=moveFile&file=${escape(currentFile)}&dest=${escape(newFilePath)}`);
     const text = await response.text();
     // console.log(text);
     if (response.ok) {
-        statusLine.textContent = `Moved '${currentFile}' to '${directory}'`;
-        history.push([currentFile, directory]);
+        if (filename != currentFile) {
+            statusLine.textContent = `Moved '${currentFile}' to '${directory}'`;
+        } else {
+            statusLine.textContent = `Moved '${currentFile}' to '${directory}' as '${filename}'`;
+        }
+        history.push([currentFile, newFilePath]);
         // remove file from list
         fileList.splice(currentFileIdx, 1);
         // set next file
@@ -237,12 +265,12 @@ async function undo() {
         statusLine.textContent = "Nothing to undo"
         return;
     }
-    const [file, directory] = history.pop();
-    const response = await fetch(`imgsort.php?action=undoFile&file=${escape(file)}&dest=${directory}`);
+    const [file, newFilePath] = history.pop();
+    const response = await fetch(`imgsort.php?action=undoFile&file=${escape(file)}&dest=${escape(newFilePath)}`);
     const text = await response.text();
     // console.log(text);
     if (response.ok) {
-        statusLine.innerHTML = `Undo: move '${file}' to '${directory}'`;
+        statusLine.textContent = `Undo: move '${file}' to '${newFilePath}'`;
         await setFileList()
         setCurrentFile();
     }
@@ -276,6 +304,11 @@ window.onload = function() {
 
 // handle keyboard
 document.onkeypress = function(e) {
+    // dont handle keys while user is typing in filename box
+    if (document.querySelector('input') === document.activeElement) {
+        return;
+    }
+
     e = e || window.event;
     let keydebug = document.getElementById("keydebug");
     if (keydebug) {