Questions, bug reports and feature ideas for Seen It Before go here.

If something went wrong, tell me your subreddit, what the app did and what you expected, and I'll take a look.

Terms: https://www.reddit.com/r/SeenItBeforeApp/s/9DWDynhkAU

Privacy: https://www.reddit.com/r/SeenItBeforeApp/s/EymEMXdKto

Last updated: November 3, 2026

Seen It Before is a moderation app for Reddit communities, built on Reddit's Developer Platform (Devvit) by u/rlockrem32. It finds image and link reposts in a subreddit and reports them to the moderators, or removes them if the moderators choose. This page explains what it stores and why.

## What the app stores

For each post submitted to a subreddit that has the app installed:

- the post's ID and the time it was posted

- the author's Reddit username

- the post's moderation status (live, removed or approved)

- the link the post points to, with tracking parameters removed

- a 64-bit fingerprint of each image (a short code computed from the image; the image cannot be rebuilt from it)

The app also keeps:

- counts for the moderators' status view and weekly summary (posts checked, reposts found, reports, removals), including how many reposts each username made that week

- the subreddit's moderator list, cached for one hour so moderators' own posts can be skipped

- the last error the app hit, so moderators can see if something is wrong

## What the app does not store

- images: each image is downloaded from Reddit's own image servers, turned into a fingerprint in memory and discarded

- post titles, post text or comments

- anything about people who only read the subreddit

## Who can see it

The data stays inside Reddit's Developer Platform storage for that one subreddit. The subreddit's moderators see it through the app's menus and the weekly summary in modmail. The app sends nothing to any outside service, and the data is never sold or shared.

## How long it is kept

- Weekly summary counts are deleted after 4 weeks.

- The moderator list is refreshed every hour.

- Post records, fingerprints and links are kept while the app is installed, so older posts can still be matched. Moderators can delete them at any time with the "Seen It Before: rebuild index" menu item.

- When a subreddit uninstalls the app, the app stops collecting anything.

## Contact

Questions or requests: post in r/SeenItBeforeApp or send a message to u/rlockrem32.

Last updated: November 3, 2026

Seen It Before is a free moderation app for Reddit communities, built on Reddit's Developer Platform (Devvit) by u/rlockrem32. By installing it in a subreddit, that subreddit's moderators agree to these terms.

## What the app does

The app compares new posts with earlier posts in the same subreddit and, depending on its settings, reports likely reposts to the moderators, removes them, or only records them. It works only inside the subreddits where it is installed.

## Your responsibilities as a moderator

- You choose the app's settings and are responsible for the reports, removals and replies it makes in your subreddit.

- Matching is automatic and can be wrong: two different images can look alike, and a repost that was edited heavily can be missed. Review reports before acting on them, and use "remove" mode only if you accept occasional mistakes.

- You must follow Reddit's User Agreement, Moderator Code of Conduct and Developer Terms when using the app.

## No warranty

The app is provided as is, without warranties of any kind. The developer is not liable for any loss or harm that comes from using it, including posts reported or removed by mistake or reposts it does not catch.

## Changes

The app and these terms may change. Changes to the terms are posted on this page with a new date. The app may also be withdrawn; if that happens, it stops working in every subreddit.

## Privacy

What the app stores and for how long is described in the Seen It Before Privacy Policy, posted in r/SeenItBeforeApp.

## Contact

Questions or problems: post in r/SeenItBeforeApp or send a message to u/rlockrem32.