diff --git a/api/api_specification.json b/api/api_specification.json
index f84f7866836c0cf8fb667cbecf78e991d5c81860..7955ce77c6d8d2bc14e48ef0aaaa40a916e4b0e0 100644
--- a/api/api_specification.json
+++ b/api/api_specification.json
@@ -2876,7 +2876,7 @@
           "file_format": {
             "config_directly_modifiable": false,
             "id": "file_format",
-            "notes": "Possible values: `mp4`, `mov`, `mkv`, `mp3`, `wav`",
+            "notes": "Possible values: `mp4`, `mov`, `mkv`, `mp3`, `wav`, `webm`",
             "object_variant": "output_file",
             "only_mod": false,
             "optional": false,
diff --git a/api/api_specification.md b/api/api_specification.md
index 324a7f26b87831d5a52dec6eb93ddb48c53e0d6a..9f64bd71a6b2005fae23123e783ea21715441334 100644
--- a/api/api_specification.md
+++ b/api/api_specification.md
@@ -1,4 +1,4 @@
-# Specification of the Web API for the Video-AG Website (v0.85).
+# Specification of the Web API for the Video-AG Website (v0.86).
 
 ## Introduction
 
@@ -2137,7 +2137,7 @@ Additionally, the following objects may appear as the type of some field:
         <td rowspan="3"><code>output_file</code></td>
         <td>file_format</td>
         <td>string</td>
-        <td>Possible values: <code>mp4</code>, <code>mov</code>, <code>mkv</code>, <code>mp3</code>, <code>wav</code></td>
+        <td>Possible values: <code>mp4</code>, <code>mov</code>, <code>mkv</code>, <code>mp3</code>, <code>wav</code>, <code>webm</code></td>
     </tr>
     <tr>
         <td>medium_file_target_id</td>
@@ -3228,6 +3228,11 @@ Possible `error_code`:
 
 ## Changelog
 
+### v0.86
+
+* Updated `ffmpeg_filter_graph_node`
+  * Added `webm` to `file_format`
+
 ### v0.85
 
 * Updated `GET /stats/publish_medium/{publish_medium_id}`
diff --git a/api/api_specification_template.md b/api/api_specification_template.md
index b177b67f8c4d72daf289a96b30b65ff2085f0628..d60bcbb1b962e6b4f958237d2e992916e39b9bb1 100644
--- a/api/api_specification_template.md
+++ b/api/api_specification_template.md
@@ -1,4 +1,4 @@
-# Specification of the Web API for the Video-AG Website (v0.85).
+# Specification of the Web API for the Video-AG Website (v0.86).
 
 ## Introduction
 
@@ -139,6 +139,11 @@ Possible `error_code`:
 
 ## Changelog
 
+### v0.86
+
+* Updated `ffmpeg_filter_graph_node`
+  * Added `webm` to `file_format`
+
 ### v0.85
 
 * Updated `GET /stats/publish_medium/{publish_medium_id}`
diff --git a/common_py/src/videoag_common/media_process/jnode/file_jnode.py b/common_py/src/videoag_common/media_process/jnode/file_jnode.py
index 29b9ac5e0cb50347d7cadf0d31860f8edaa8b27e..3ef28acc9b4c61e8660a667778207cd3e214d4b7 100644
--- a/common_py/src/videoag_common/media_process/jnode/file_jnode.py
+++ b/common_py/src/videoag_common/media_process/jnode/file_jnode.py
@@ -231,6 +231,7 @@ class OutputFileFormat(JsonSerializableEnum):
     MKV = "mkv"
     MP3 = "mp3"
     WAV = "wav"
+    WEBM = "webm"
 
 
 class OutputCodec(JsonSerializableEnum):