1. Supported Video Formats & Encoding Restrictions

Reddit’s video pipeline effectively expects MP4 containers using H.264 video and AAC audio; anything else is either rejected or forcefully re‑encoded, often with noticeable quality loss. Starting from compliant source files gives you much better control over final quality than letting Reddit transcode from formats like WebM, MOV, or AVI.

Key Encoding Constraints

• Max file size around 1 GB.
• Max effective resolution around 1080p; higher uploads are downscaled.
• Max frame rate about 30 fps; higher frame rates are capped.
• Dynamic bitrate compression applied on Reddit’s side.

2. Reddit API Media Upload Process

The Reddit API uses a staged upload flow, where you first request a signed media upload URL, then PUT the binary video to that URL, and finally create the post referencing the uploaded media asset. This pattern mirrors other S3‑backed upload systems and keeps large file transfers off the core API domain.

Step 1: Request an Upload URL

Call the media asset upload endpoint with the filename and MIME type for your MP4 video.

POST https://www.reddit.com/api/media_asset_upload_request
{
  "filepath": "video.mp4",
  "mimetype": "video/mp4"
}

The response includes a signed S3 URL you will use to upload the actual video file.

Step 2: Upload the Video to the Signed URL

Use a raw HTTP PUT with the correct content type and binary data to send the file to the signed URL.

curl -X PUT \
  -H "Content-Type: video/mp4" \
  --data-binary "@video.mp4" \
  "SIGNED_URL_FROM_STEP_1"

Step 3: Submit the Video Post

After the upload completes, submit the post via the standard submit endpoint, passing the media asset URL or identifier.

POST https://www.reddit.com/api/submit
{
  "kind": "video",
  "url": "MEDIA_ASSET_URL",
  "title": "My Reddit Video",
  "sr": "subreddit_name"
}

3. Encoding Limitations & How Reddit Compresses Videos

Regardless of input, Reddit runs uploaded videos through its own transcoding pipeline, which typically reduces bitrate, caps resolution to around 1080p, and enforces a 30 fps ceiling. Audio is also recompressed, usually at moderate AAC bitrates to balance clarity and size.

In practice, you get better visual stability by matching Reddit’s target profile in your export, rather than pushing high‑end specs that will only be dialed back later in the pipeline.

4. How to Optimize Videos for Reddit Using FFmpeg & HandBrake

Before hitting the API, it is worth normalizing your videos with FFmpeg or HandBrake so they comply with Reddit’s expectations and do not trigger avoidable errors or heavy transcoding. The goal is MP4, H.264, AAC, 1080p, 30 fps, and a moderate bitrate.

FFmpeg Command for Optimizing Reddit Videos

ffmpeg -i input.mp4 \
  -c:v libx264 -crf 23 -preset fast \
  -c:a aac -b:a 128k \
  -r 30 \
  -vf "scale=1920:-2" \
  output.mp4

Here, the CRF value around 23 balances size and visual quality, the “fast” preset speeds up encoding, the 128 kbps AAC track preserves acceptable audio, the 30 fps frame rate matches Reddit’s cap, and the scaling filter constrains resolution around 1080p.

HandBrake Settings for Reddit Video Uploads

• Format: MP4 container, with “Web Optimized” enabled.
• Video codec: H.264, constant frame rate at 30 fps.
• Quality: RF around 22–24 for general content.
• Audio: AAC at 128–160 kbps, stereo mix.

Using these targets keeps your uploads within Reddit’s comfort zone while retaining as much detail as the platform’s compression allows.

5. Reddit API Rate Limits & Workarounds

Reddit enforces both general API request quotas and more practical limits on media uploads per account over a short period to prevent abuse. In many automation setups, sticking to a handful of video uploads per hour per user and spacing out calls keeps you clear of errors.

When you design scripts, monitoring response headers and logging rate‑limit responses makes it easier to tune intervals before users encounter hard failures.

6. Common Reddit API Video Upload Errors & Fixes

Most upload failures come from unsupported formats, oversized files, expired signed URLs, or hitting implicit rate limits. Mapping your error handling to these categories helps keep automation resilient.

Check These Related Guides

For workflows that combine downloading, compressing, and re‑uploading Reddit videos, it helps to link deeper tutorials from this page.

• Best Reddit Video Downloaders
• How to Compress Downloaded Videos
• Understanding Video Codecs & Compression