diff --git a/OpenNest.Data/NestStorageSettings.cs b/OpenNest.Data/NestStorageSettings.cs
index f092c5d..f15cf19 100644
--- a/OpenNest.Data/NestStorageSettings.cs
+++ b/OpenNest.Data/NestStorageSettings.cs
@@ -32,6 +32,18 @@ public sealed class NestStorageSettings
     public bool IsDatabaseMode =>
         Mode == NestStorageMode.Database && !string.IsNullOrWhiteSpace(ServerUrl);
 
+    /// <summary>Validate and normalize a nest server base URL without changing storage mode.</summary>
+    public static bool TryNormalizeServerUrl(string? url, out string normalized)
+    {
+        normalized = NormalizeUrl(url);
+        if (Uri.TryCreate(normalized, UriKind.Absolute, out var uri)
+            && (uri.Scheme == Uri.UriSchemeHttp || uri.Scheme == Uri.UriSchemeHttps))
+            return true;
+
+        normalized = "";
+        return false;
+    }
+
     /// <summary>%APPDATA%\OpenNest\storage.json.</summary>
     public static string DefaultPath => Path.Combine(
         Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
diff --git a/OpenNest.Tests/Data/NestStorageTests.cs b/OpenNest.Tests/Data/NestStorageTests.cs
index 1a41586..b7a33f9 100644
--- a/OpenNest.Tests/Data/NestStorageTests.cs
+++ b/OpenNest.Tests/Data/NestStorageTests.cs
@@ -59,6 +59,31 @@ public class NestStorageSettingsTests : IDisposable
         Assert.False(settings.IsDatabaseMode);
     }
 
+    [Fact]
+    public void TryNormalizeServerUrl_AcceptsHttpsWithoutChangingMode()
+    {
+        var settings = new NestStorageSettings { Mode = NestStorageMode.File };
+
+        Assert.True(NestStorageSettings.TryNormalizeServerUrl(" https://shop.example:8090/ ", out var url));
+        settings.ServerUrl = url;
+        settings.Save(FilePath);
+
+        var loaded = NestStorageSettings.Load(FilePath);
+        Assert.Equal("https://shop.example:8090", loaded.ServerUrl);
+        Assert.Equal(NestStorageMode.File, loaded.Mode);
+        Assert.False(loaded.IsDatabaseMode);
+    }
+
+    [Theory]
+    [InlineData("")]
+    [InlineData("ftp://shop.example")]
+    [InlineData("not-a-url")]
+    public void TryNormalizeServerUrl_RejectsInvalidAddress(string input)
+    {
+        Assert.False(NestStorageSettings.TryNormalizeServerUrl(input, out var url));
+        Assert.Equal("", url);
+    }
+
     public void Dispose()
     {
         if (Directory.Exists(_directory))
diff --git a/OpenNest/Forms/MainForm.cs b/OpenNest/Forms/MainForm.cs
index 938e7fc..f7bf2da 100644
--- a/OpenNest/Forms/MainForm.cs
+++ b/OpenNest/Forms/MainForm.cs
@@ -646,6 +646,7 @@ namespace OpenNest.Forms
                 var serverUrl = NestStorage.Settings.ServerUrl;
                 databaseOpenInProgress = true;
                 storageModeMenu.Enabled = false;
+                mnuToolsOptions.Enabled = false;
                 var file = await repository.GetFileAsync(dlg.SelectedId);
                 if (file == null)
                     throw new FileNotFoundException("This nest no longer exists on the server.");
@@ -663,7 +664,10 @@ namespace OpenNest.Forms
             {
                 databaseOpenInProgress = false;
                 if (!IsDisposed)
+                {
                     storageModeMenu.Enabled = !databaseSaveInProgress;
+                    mnuToolsOptions.Enabled = !databaseSaveInProgress;
+                }
             }
         }
 
@@ -707,6 +711,7 @@ namespace OpenNest.Forms
         {
             databaseSaveInProgress = true;
             storageModeMenu.Enabled = false;
+            mnuToolsOptions.Enabled = false;
             EnableCheck();
             try
             {
@@ -729,6 +734,7 @@ namespace OpenNest.Forms
                 if (!IsDisposed)
                 {
                     storageModeMenu.Enabled = !databaseOpenInProgress;
+                    mnuToolsOptions.Enabled = !databaseOpenInProgress;
                     EnableCheck();
                 }
             }
diff --git a/OpenNest/Forms/OptionsForm.Designer.cs b/OpenNest/Forms/OptionsForm.Designer.cs
index 3425726..47e5dd0 100644
--- a/OpenNest/Forms/OptionsForm.Designer.cs
+++ b/OpenNest/Forms/OptionsForm.Designer.cs
@@ -41,9 +41,13 @@
             this.strategyGroupBox = new System.Windows.Forms.GroupBox();
             this.colorSchemeLabel = new System.Windows.Forms.Label();
             this.colorSchemeCombo = new System.Windows.Forms.ComboBox();
+            this.serverGroupBox = new System.Windows.Forms.GroupBox();
+            this.serverUrlBox = new System.Windows.Forms.TextBox();
+            this.setServerButton = new System.Windows.Forms.Button();
             ((System.ComponentModel.ISupportInitialize)(this.numericUpDown1)).BeginInit();
             this.tableLayoutPanel1.SuspendLayout();
             this.bottomPanel1.SuspendLayout();
+            this.serverGroupBox.SuspendLayout();
             this.SuspendLayout();
             // 
             // checkBox1
@@ -135,7 +139,7 @@
             this.bottomPanel1.Controls.Add(this.cancelButton);
             this.bottomPanel1.Controls.Add(this.saveButton);
             this.bottomPanel1.Dock = System.Windows.Forms.DockStyle.Bottom;
-            this.bottomPanel1.Location = new System.Drawing.Point(0, 368);
+            this.bottomPanel1.Location = new System.Drawing.Point(0, 443);
             this.bottomPanel1.Name = "bottomPanel1";
             this.bottomPanel1.Size = new System.Drawing.Size(708, 50);
             this.bottomPanel1.TabIndex = 1;
@@ -158,7 +162,7 @@
             // strategyGroupBox
             //
             this.strategyGroupBox.Controls.Add(this.strategyGrid);
-            this.strategyGroupBox.Location = new System.Drawing.Point(12, 178);
+            this.strategyGroupBox.Location = new System.Drawing.Point(12, 253);
             this.strategyGroupBox.Name = "strategyGroupBox";
             this.strategyGroupBox.Size = new System.Drawing.Size(684, 180);
             this.strategyGroupBox.TabIndex = 2;
@@ -184,13 +188,43 @@
             this.colorSchemeCombo.Size = new System.Drawing.Size(130, 24);
             this.colorSchemeCombo.TabIndex = 11;
             //
+            // serverGroupBox
+            //
+            this.serverGroupBox.Controls.Add(this.serverUrlBox);
+            this.serverGroupBox.Controls.Add(this.setServerButton);
+            this.serverGroupBox.Location = new System.Drawing.Point(12, 178);
+            this.serverGroupBox.Name = "serverGroupBox";
+            this.serverGroupBox.Size = new System.Drawing.Size(684, 69);
+            this.serverGroupBox.TabIndex = 1;
+            this.serverGroupBox.TabStop = false;
+            this.serverGroupBox.Text = "Nest server URL (File / Database mode is selected under File > Storage Mode)";
+            //
+            // serverUrlBox
+            //
+            this.serverUrlBox.Location = new System.Drawing.Point(12, 29);
+            this.serverUrlBox.Name = "serverUrlBox";
+            this.serverUrlBox.PlaceholderText = "http://server:8090";
+            this.serverUrlBox.Size = new System.Drawing.Size(485, 22);
+            this.serverUrlBox.TabIndex = 0;
+            //
+            // setServerButton
+            //
+            this.setServerButton.Location = new System.Drawing.Point(504, 26);
+            this.setServerButton.Name = "setServerButton";
+            this.setServerButton.Size = new System.Drawing.Size(168, 28);
+            this.setServerButton.TabIndex = 1;
+            this.setServerButton.Text = "Set / Change Server";
+            this.setServerButton.UseVisualStyleBackColor = true;
+            this.setServerButton.Click += new System.EventHandler(this.SetServer_Click);
+            //
             // OptionsForm
             //
             this.AcceptButton = this.saveButton;
             this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.None;
             this.CancelButton = this.cancelButton;
-            this.ClientSize = new System.Drawing.Size(708, 418);
+            this.ClientSize = new System.Drawing.Size(708, 493);
             this.Controls.Add(this.strategyGroupBox);
+            this.Controls.Add(this.serverGroupBox);
             this.Controls.Add(this.tableLayoutPanel1);
             this.Controls.Add(this.bottomPanel1);
             this.Font = new System.Drawing.Font("Microsoft Sans Serif", 9.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
@@ -206,6 +240,8 @@
             this.tableLayoutPanel1.ResumeLayout(false);
             this.tableLayoutPanel1.PerformLayout();
             this.bottomPanel1.ResumeLayout(false);
+            this.serverGroupBox.ResumeLayout(false);
+            this.serverGroupBox.PerformLayout();
             this.ResumeLayout(false);
 
         }
@@ -224,5 +260,8 @@
         private System.Windows.Forms.GroupBox strategyGroupBox;
         private System.Windows.Forms.Label colorSchemeLabel;
         private System.Windows.Forms.ComboBox colorSchemeCombo;
+        private System.Windows.Forms.GroupBox serverGroupBox;
+        private System.Windows.Forms.TextBox serverUrlBox;
+        private System.Windows.Forms.Button setServerButton;
     }
 }
\ No newline at end of file
diff --git a/OpenNest/Forms/OptionsForm.cs b/OpenNest/Forms/OptionsForm.cs
index 1ea4579..95fec44 100644
--- a/OpenNest/Forms/OptionsForm.cs
+++ b/OpenNest/Forms/OptionsForm.cs
@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Windows.Forms;
+using OpenNest.Data;
 using OpenNest.Engine.Strategies;
 using OpenNest.Properties;
 
@@ -72,6 +73,7 @@ namespace OpenNest.Forms
 
         private void LoadSettings()
         {
+            serverUrlBox.Text = NestStorage.Settings.ServerUrl;
             checkBox1.Checked = Settings.Default.CreateNewNestOnOpen;
             numericUpDown1.Value = (decimal)Settings.Default.AutoSizePlateFactor;
 
@@ -142,5 +144,28 @@ namespace OpenNest.Forms
         {
             SaveSettings();
         }
+
+        private void SetServer_Click(object sender, EventArgs e)
+        {
+            if (!NestStorageSettings.TryNormalizeServerUrl(serverUrlBox.Text, out var url))
+            {
+                MessageBox.Show(this, "Enter a valid http or https server URL.",
+                    "Server URL", MessageBoxButtons.OK, MessageBoxIcon.Warning);
+                return;
+            }
+
+            try
+            {
+                NestStorage.Save(NestStorage.Settings.Mode, url);
+                serverUrlBox.Text = NestStorage.Settings.ServerUrl;
+                MessageBox.Show(this, "Server URL saved. Storage mode has not changed.",
+                    "Server URL", MessageBoxButtons.OK, MessageBoxIcon.Information);
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show(this, $"Could not save the server URL: {ex.Message}",
+                    "Server URL", MessageBoxButtons.OK, MessageBoxIcon.Error);
+            }
+        }
     }
 }
diff --git a/docs/nest-storage.md b/docs/nest-storage.md
index e30b588..e831cb9 100644
--- a/docs/nest-storage.md
+++ b/docs/nest-storage.md
@@ -241,6 +241,10 @@ curl --fail http://<bind-address>:<port>/healthz  # {"status":"ok"}
 
 In the desktop app choose **File > Storage Mode...**, Database, and enter the base
 URL `http://<bind-address>:<port>`, without `/healthz` or `/api/nests`.
+To set or change just the saved server address without changing File/Database mode,
+use **Tools > Options > Nest server URL > Set / Change Server**. This saves the URL
+immediately, independently of the Options Save button; it does not migrate nests
+or enable Database mode. Canceling Options afterward does not undo that address.
 
 ### Backup, restore, and upgrade