SWF to MP4 Converter
Convert SWF files that contain a video, such as screen recordings, video clips and slideshows exported from Flash, to MP4 that plays on any phone, computer or TV, with full control over quality, bitrate, frame rate, resolution and audio. SWF games and drawn animations cannot be converted here — see the notes below.
Also: MKV to MP4 converter · AVI to MP4 converter · MOV to MP4 converter · WebM to MP4 converter · FLV to MP4 converter · TS to MP4 converter · WMV to MP4 converter · MPEG to MP4 converter · 3GP to MP4 converter · M4V to MP4 converter · MOD to MP4 converter · VOB to MP4 converter · MTS to MP4 converter · OGV to MP4 converter · RM/RMVB to MP4 converter · MXF to MP4 converter · DV to MP4 converter · F4V to MP4 converter · MP4 compressor · Video to MP3 extractor · MP4 to GIF converter · Video format converter
Click to choose a video, or drag and drop
Choose a SWF file that contains video — FLV, MP4, MKV, AVI and most other formats are accepted too. Stays on your device.
Your video is converted entirely in your browser and is never uploaded. The converter engine (ffmpeg, ~32 MB) is downloaded once and cached by your browser.
Frequently asked questions
What can this tool convert, and what can't it?
A SWF file is a container that can hold three different things. It converts SWFs that contain a recorded video or a series of pictures with sound, which is what many old screen-recording tools, video-to-Flash converters and Flash video players produced. It cannot convert SWFs made of vector drawings, scripts and interactive content, such as Flash games, banners, menus and cartoons drawn in Flash, because those are programs that need a Flash player to draw each frame. If your file has no video inside, the tool tells you so instead of producing an empty MP4.
How can I tell if my SWF contains video?
Just try it. The tool reads the file and lists the video and audio it finds. If it shows a video stream with a size and frame rate, the file will convert. If it reports no video, the SWF is an animation or program rather than a recorded video.
Can I convert a Flash cartoon or game to MP4?
Not with this tool. Turning a drawn Flash animation into video means running it in a Flash player and recording the screen. The Flash Player is discontinued, but a community player called Ruffle can run many SWF files in a browser, and a screen recorder can then capture it as video.
Why is the duration missing or the progress bar not moving?
SWF files do not store their total length in a way the converter can read in advance, so the length is shown as unknown and progress is approximate. The conversion still completes. Use Start and End if you only need part of the file.
Is it safe to open an old SWF file?
The file is only read as data and never run, so nothing in it can execute on your computer. The conversion happens in your browser and the file is not uploaded.
Is my video uploaded anywhere?
No. The conversion runs entirely in your browser using ffmpeg compiled to WebAssembly. Your video never leaves your device. Only the converter engine itself (about 32 MB) is downloaded, once, and cached by your browser.
What is Fast remux and when should I use it?
A SWF file is just a container. If the video inside is H.264 (or another format MP4 supports) and the audio is AAC, MP3 or AC-3, those streams can be moved into an MP4 container as they are. That takes seconds and loses no quality at all. The tool checks your file and picks this automatically when it is possible.
What do CRF and bitrate mean?
CRF (constant quality) lets the encoder spend as many bits as each scene needs: lower numbers mean better quality and bigger files, around 18 looks near-lossless, 23 is the default and 28 is noticeably smaller. A target bitrate instead aims for a fixed number of kilobits per second, which gives a predictable file size but variable quality.
Why is re-encoding slow, and is there a size limit?
Re-encoding runs on a single CPU thread inside the browser (H.264 only), so it is usually near real-time speed or slower for HD. The finished MP4 also has to fit in browser memory, which in practice limits output to roughly 1 to 2 GB. For a long movie, use Fast remux, trim it, or copy the generated command and run it with ffmpeg on your own computer.
What happens to subtitles?
MP4 supports text subtitles only. SRT, ASS/SSA and WebVTT tracks are converted to the MP4 text format, and you can also save a track as a separate .srt file. Picture-based subtitles from Blu-ray or DVD (PGS, VobSub) cannot be converted.