From a7d8d13d9a9f0bdbe15f223d66e2dc5af16290cc Mon Sep 17 00:00:00 2001
From: Kai Curry <kai@familiar.media>
Date: Mon, 23 Feb 2026 12:45:29 -0100
Subject: [PATCH] docs: Add frame selection and clean copy details to snapshots
 docs (#21946)

* docs: Add frame selection and clean copy details to snapshots docs

Document how Frigate selects the best frame for snapshots, explain the
difference between regular snapshots and clean copies, fix internal
links to use absolute paths, and highlight Frigate+ as the primary
reason to keep clean_copy enabled if regular snapshot is configured clean.

* revert - do not use the word event

* rm clean copy is only saved when `clean_copy` is enabled

* Simplified the Frame Selection section down to a single paragraph.

* rm note about snapshot file ext change from png to webp

---------

Co-authored-by: Kai Curry <kai@wjerk.com>
---
 docs/docs/configuration/snapshots.md | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/docs/docs/configuration/snapshots.md b/docs/docs/configuration/snapshots.md
index 815e301ba..01c034a04 100644
--- a/docs/docs/configuration/snapshots.md
+++ b/docs/docs/configuration/snapshots.md
@@ -9,4 +9,25 @@ Snapshots are accessible in the UI in the Explore pane. This allows for quick su
 
 To only save snapshots for objects that enter a specific zone, [see the zone docs](./zones.md#restricting-snapshots-to-specific-zones)
 
-Snapshots sent via MQTT are configured in the [config file](https://docs.frigate.video/configuration/) under `cameras -> your_camera -> mqtt`
+Snapshots sent via MQTT are configured in the [config file](/configuration) under `cameras -> your_camera -> mqtt`
+
+## Frame Selection
+
+Frigate does not save every frame — it picks a single "best" frame for each tracked object and uses it for both the snapshot and clean copy. As the object is tracked across frames, Frigate continuously evaluates whether the current frame is better than the previous best based on detection confidence, object size, and the presence of key attributes like faces or license plates. Frames where the object touches the edge of the frame are deprioritized. The snapshot is written to disk once tracking ends using whichever frame was determined to be the best.
+
+MQTT snapshots are published more frequently — each time a better thumbnail frame is found during tracking, or when the current best image is older than `best_image_timeout` (default: 60s). These use their own annotation settings configured under `cameras -> your_camera -> mqtt`.
+
+## Clean Copy
+
+Frigate can produce up to two snapshot files per event, each used in different places:
+
+| Version | File | Annotations | Used by |
+| --- | --- | --- | --- |
+| **Regular snapshot** | `<camera>-<id>.jpg` | Respects your `timestamp`, `bounding_box`, `crop`, and `height` settings | API (`/api/events/<id>/snapshot.jpg`), MQTT (`<camera>/<label>/snapshot`), Explore pane in the UI |
+| **Clean copy** | `<camera>-<id>-clean.webp` | Always unannotated — no bounding box, no timestamp, no crop, full resolution | API (`/api/events/<id>/snapshot-clean.webp`), [Frigate+](/plus/first_model) submissions, "Download Clean Snapshot" in the UI |
+
+MQTT snapshots are configured separately under `cameras -> your_camera -> mqtt` and are unrelated to the clean copy.
+
+The clean copy is required for submitting events to [Frigate+](/plus/first_model) — if you plan to use Frigate+, keep `clean_copy` enabled regardless of your other snapshot settings.
+
+If you are not using Frigate+ and `timestamp`, `bounding_box`, and `crop` are all disabled, the regular snapshot is already effectively clean, so `clean_copy` provides no benefit and only uses additional disk space. You can safely set `clean_copy: False` in this case.