diff --git a/README.md b/README.md
index 1c1b1b110..329d658aa 100644
--- a/README.md
+++ b/README.md
@@ -61,7 +61,7 @@ any help with getting started, I'm available most days.
 
 1. Install Docker and Docker Compose - [Windows install instructions](https://docs.docker.com/docker-for-windows/install/)
 
-1. Install the dotnet SDK, currently 8.x
+1. Install the dotnet SDK, currently 9.x
 
 1. Log in or sign up for a [Battle.Net Developer](https://develop.battle.net) account
 
@@ -119,7 +119,7 @@ any help with getting started, I'm available most days.
 1. Start the initial data import/build, this will take a while:
 
     ```bash
-    cd app/tool/
+    cd apps/tool/
     dotnet run all
     ```
 
diff --git a/apps/frontend/components/tooltips/character-filter/TooltipCharacterFilter.svelte b/apps/frontend/components/tooltips/character-filter/TooltipCharacterFilter.svelte
index 30c37b930..f173eeb87 100644
--- a/apps/frontend/components/tooltips/character-filter/TooltipCharacterFilter.svelte
+++ b/apps/frontend/components/tooltips/character-filter/TooltipCharacterFilter.svelte
@@ -48,6 +48,11 @@
                 <code>level=60 | &lt;=,&lt;,=,&gt;,&gt;=</code>
             </dd>
 
+            <dt>Last seen (days)</dt>
+            <dd>
+                <code>seen&lt;=7 | &lt;=,&lt;,=,&gt;,&gt;=</code>
+            </dd>
+
             <dt>Item Level</dt>
             <dd>
                 <code>ilevel&gt;=400 | &lt;=,&lt;,=,&gt;,&gt;=</code>
diff --git a/apps/frontend/user-home/components/settings/sections/views/Sorting.svelte b/apps/frontend/user-home/components/settings/sections/views/Sorting.svelte
index 221d20921..1143caed4 100644
--- a/apps/frontend/user-home/components/settings/sections/views/Sorting.svelte
+++ b/apps/frontend/user-home/components/settings/sections/views/Sorting.svelte
@@ -23,6 +23,7 @@
         { id: 'gold', name: 'Gold' },
         { id: 'itemlevel', name: 'Item level' },
         { id: 'level', name: 'Level' },
+        { id: 'seen', name: 'Last seen' },
     ];
 
     let sortByChoices: SettingsChoice[] = $derived([
diff --git a/apps/frontend/utils/characters/use-character-filter.ts b/apps/frontend/utils/characters/use-character-filter.ts
index 45172aff8..f9566ddd4 100644
--- a/apps/frontend/utils/characters/use-character-filter.ts
+++ b/apps/frontend/utils/characters/use-character-filter.ts
@@ -61,6 +61,19 @@ export function useCharacterFilter(
                                 );
                             }
 
+                            // Last seen (in days)
+                            match = part.match(/^seen(<|<=|=|>=|>)(\d+)$/);
+                            if (match) {
+                                const now = Math.floor(Date.now() / 1000);
+                                const days = parseInt(match[2]);
+                                const diff = (now - char.lastSeenAddonUnix) / 86400;
+                                return compareValues(
+                                    match[1].toString(),
+                                    diff,
+                                    days
+                                );
+                            }
+
                             // Item level
                             match = part.match(/^(itemlevel|ilevel|ilvl)(<|<=|=|>=|>)(\d+)$/);
                             if (match) {
diff --git a/apps/frontend/utils/get-character-sort-func.ts b/apps/frontend/utils/get-character-sort-func.ts
index 8346887e8..a61823aac 100644
--- a/apps/frontend/utils/get-character-sort-func.ts
+++ b/apps/frontend/utils/get-character-sort-func.ts
@@ -86,6 +86,8 @@ export const getCharacterSortFunc = (prefixFunc?: SortValueFunction, viewSortBy?
                         '0'
                     )
                 );
+            } else if (thing === 'seen') {
+                out.push(leftPad(2000000000 - char.lastSeenAddonUnix, 10, '0'));
             } else if (thing === 'level') {
                 // in descending order
                 const levelData = getCharacterLevel(char);