FLV → YouTube Shorts
Compress FLV for YouTube Shorts
Compressing FLV for YouTube Shorts comes down to three constraints: YouTube Shorts's 4 GB cap, its 1080:1920 resolution ceiling, and the need to output MP4 H.264 for reliable inline playback. FLV source files are typically 480p (legacy Flash Video) at around 15 MB per minute — right at YouTube Shorts's 500 MB target. We calculate a per-clip bitrate budget from your duration, subtract 192 kbps for audio, and allocate the remainder to H.264 video at the highest quality that fits. FLV's H.263 or Sorenson Spark video gets replaced with H.264; the format is obsolete and no modern platform plays it. YouTube Shorts does not play FLV inline, so this page does a format conversion (FLV → MP4 H.264) plus the size compression in a single pass.
Where do you want to share your video?
How to compress FLV for YouTube Shorts
- 1Drag your .flv file onto the upload zone above (or browse to it).
- 2YouTube Shorts is already selected — we'll target 500 MB to stay safely under the 4 GB cap.
- 3Optionally trim to a highlight clip or switch to H.265 for 30-50% smaller files at the same quality.
- 4Download the compressed MP4 and share it on YouTube Shorts. Source file auto-deletes from our servers after 1 hour.
What to know about FLV → YouTube Shorts
- FLV's H.263 or Sorenson Spark video gets replaced with H.264; the format is obsolete and no modern platform plays it.
- Resolution is kept at up to 1920p when the bitrate budget allows.
- Trim to the highlight before you compress — every 10 seconds you cut gives remaining frames more bitrate to work with.
- YouTube Shorts's 500 MB target leaves a 5% safety margin below its 4 GB hard cap, so platform-side rejection is never an issue.
The compression math
A 1-minute FLV at 480p (legacy Flash Video) = ~15 MB. YouTube Shorts's 500 MB target minus 192 kbps audio = ~69713 kbps video budget. H.264 at that budget kept at up to 1920p when the bitrate budget allows produces a file at the target size that plays inline on YouTube Shorts.
About FLV files
FLV (Flash Video) was the dominant web video format from 2005 to 2015, used by early YouTube, Newgrounds, and countless Flash-based websites. With Flash Player's discontinuation in 2020, FLV files cannot play in any modern browser or device without conversion. CompressYourVideo.com converts FLV to compressed MP4, making your old Flash videos playable again on every device. This is essential for anyone with archives of old web video downloads, Flash game recordings, or early YouTube saves. The conversion typically reduces file size while dramatically improving compatibility, since modern H.264 encoding is far more efficient than the codecs used in FLV files from the 2000s.
About YouTube Shorts
Compress and format videos for YouTube Shorts. Shorts require 9:16 vertical format, up to 3 minutes, and look best at 1080×1920. Our tool crops, compresses, and outputs the right specs.
Related compression tools
Or compress FLV for a different platform