Simple 4chan Encoder

A fast, no-fuss .webm maker for 4chan (Windows only)

Simple 4chan Encoder is a lightweight but powerful tool for making high-quality .webm videos under 4 MB — perfect for posting on 4chan. Just drop in any video and get a 4chan-friendly result.

Features

🎯 Automatic Bitrate Targeting (4 MB Limit)

No more guessing bitrate values — the app calculates it for you based on your video length.

A -1% safety margin is applied to the calculated bitrate, ensuring that videos will never exceed the 4 MB limit, even if just by a tiny amount.
There's also an alternative safety margin that is applied only to videos with variable frame rate, since these are trickier.

🛡 Quality Guarantee (-qmin 15)

The encoder ensures videos never exceed a certain quality level:

4MB might be overkill for very short and/or low resolution clips, to remediate that, the script has a default Quantization Scale value of 15. This ensures very short and/or low resolution clips end up with an acceptable file size, while longer and/or high res videos look great (as long as you keep in mind we are working with 4MB, so keep longer videos with a lower resolution, and high res videos short in duration).

I found q=15 to work really well as a middle ground for 4MB files.

🖼 Intuitive Video Editor

An optional built-in GUI makes trimming, cropping, and scaling a breeze.

💬 Subtitle Support

Select a subtitle track from your source video and burn it directly into the output.

📀 VP9 Two-Pass Encoding

Uses the libvpx-vp9 codec with slow two-pass encoding for maximum quality at our target size.

How to Use

1. Run the .exe – A command prompt opens.
2. Add Your Video – Drag & drop the file, then press Enter.
3. Need anything else? – Type y to open the GUI editor, or n to skip straight to encoding.
4. (If Using the GUI):
   • Trim: Set start/end points
   • Crop: Enable cropping & adjust
   • Scale: Change resolution
   • Subs: Burn subtitles (only visible if the video file contains soft subs)
   • Loop: Preview trimmed section in a loop
5. Encode – Click Encode and watch progress.
6. Done – Now you can play the result, open the videos folder, or simply close the app in the post-encode actions.

Under the Hood

• Core: Python
• Video Processing: ffmpeg, ffprobe
• Video Playback: python-mpv
• GUIs: PyQt6

Downloads

https://files.catbox.moe/2p0cyf.zip
https://mega.nz/file/pRxS1RrL#k1Vdsqa3DkLcCOC9vBvHNi3V297lklFQJWM5HtOMUAk

Changelog

31/08/2025 - v1.4
-added version file

19/08/2025 - v1.3
-decreased default bitrate safety margin from 5% to 1%
-added an alternative bitrate safety margin for videos with variable frame rate
-migrated encoding window to PyQt6
-fixed behavior of some soft sub formats on the video preview
-fixed minor bugs

15/08/2025 - v1.2
-subtitle checkbox and selection moved to the bottom of the video editor window
-added "Open with" functionality

13/08/2025 - v1.1
-fixed some softsub formats causing an error during encoding
-the close (X) button of the encoding window is now disabled until the encode is finished
-canceling an encode in progress will now auto delete the unfinished video file
-the preview mode toggle button is now always visible

11/08/2025 - v1.0
-initial release

86e23Q5EK5QMUdoiCDnvPain7fx4jTgbEPicZ51wbmT33maj6tHbUKMWeX4EyZhPgveG4fQmKdPAwDVHPv3Wp6ibDKbXXfV