# Clear-Metadata

> [!toc] Table of Contents
>
> <!-- toc -->

> [!tip] Tip {static}
>
> If you don't know exactly what metadata is, read the
>
> [article](https://wiki.aktivismus.org/books/it-sicherheit-esc-it/page/meta-data) about this threat.

The following is mostly taken from the entry on metadata in the
[Systemli Wiki](https://wiki.systemli.org/howto/metadata).

## Exifcleaner

Platform: Linux, Mac, Windows [Exifcleaner](https://exifcleaner.com/) is an application
for removing metadata from files.

## Metadata Cleaner

Platform: Linux [Metadata Cleaner](https://metadatacleaner.romainvigier.fr/) is a
popular program for deleting all metadata from various file formats with a single click.
It supports all common file formats and is very easy to use. It is based on Mat2, which
is presented here. Mat2 is particularly interesting to us because of its web
application, which can be a good alternative for on the go.

### Mat2

Platform: Web browser (online, all systems) and file manager (offline, Linux)

[Mat2](https://0xacab.org/jvoisin/mat2) is pre-installed on the anonymous operating
system Tails and can be installed on other Linux systems. Instead of being a standalone
program, mat2 is installed as an extension for the file browser and used by
right-clicking on the file to be cleaned up.
![screenshot of mat2 in file browser](https://esc-it.org/assets/articles/en/recommendations/clear-metadata/mat2-demo.png)

#### Web application

You can also use mat2 without installation as a web application at
<https://metadata.systemli.org>. The files are uploaded to the Systemli server, cleaned
up there, and then you can download them again. The web application is therefore an
alternative for when you are on the go.

## Scrambled Exif

Platform: Android

[Scrambled Exif](https://gitlab.com/juanitobananas/scrambled-exif#scrambled-exif) is an
open-source app for cleaning up image files. You can download the app from the Google
Play Store or F-Droid. After installation, you need to open the app once and give it
permission to access your storage in order to set it up. Then, every time you want to
share an image, you can share it via Scrambled Exif. It will clean up the file and ask
you which app you want to share the cleaned file with.

## Printerdots

As described at [HacksAndLeaks](https://hacksandleaks.com/chapter-1.html): Instead of
uploading original documents whose printer dots could reveal your identity, it is better
to type or reproduce the originals by hand, print them on an “anonymous” printer, and
publish them that way.

## Anonymize scanned documents

### Okular

Platform: Linux, Windows, (MacOS officially only with unstable version, but works quite
well according to experience)

Okular is a PDF viewer that can also be used to black out documents.

### Obfuscate

Platform: Linux

With [Obfuscate](https://gitlab.gnome.org/World/obfuscate/), image files can be reliably
pixelated/blacked out.

### Libre Office

Documents can also be blacked out with Libre Office. However, most people find the above
methods much more intuitive and simpler. An older but very good English-language guide
can be
[found here](https://web.archive.org/web/20210216143417/https://infosec-handbook.eu/blog/libreoffice63-redaction/).