RunConvert

SWF to MKV Converter

Convert SWF to MKV online for free. Fast, secure, and high-quality conversion with no sign-up or software required.

Free to useNo file stored beyond 1 hourEncrypted over TLS 1.2/1.3No watermarks

How it works

Three steps to your converted file

Everything happens in your browser tab - upload, pick a format, download. The heavy lifting runs on our servers.

01

Upload your file

Drag and drop, click to browse, or paste a URL. Batches take up to 20 files at once - 230+ input formats across video, audio, image, document, and archive types.

02

Choose an output format

Pick from over a hundred output formats. Filter by category or search by name - every option is open to everyone, no account needed.

03

Convert & download

Hit Convert and grab your download link moments later. Originals are erased when the job completes; results are cleared within about an hour.

What is an SWF file?

SWF (Small Web Format, originally Shockwave Flash) is a binary file format for multimedia, vector graphics, and ActionScript execution, originally developed by FutureWave Software and later acquired by Adobe Systems. It serves as the compiled delivery format for Adobe Animate (formerly Flash) and relies on the SWF file structure specification to define tags for display lists and control bytes. Adobe officially ended support (End of Life) for the Flash Player runtime on December 31, 2020, rendering SWF files obsolete for web use due to security vulnerabilities and the shift to HTML5 standards.

How to open an SWF file

Modern web browsers (Chrome, Edge, Safari) strictly block SWF execution. To open legacy SWF files, users must rely on the standalone Adobe Flash Player Projector (content debugger) or open-source emulators like Ruffle, which runs Flash content via WebAssembly. For video-only SWF files not relying on complex ActionScript interactivity, VLC media player can often decode the embedded video streams.

SWF Technical Info

Full Name
Small Web Format
Developed By
FutureWave / Macromedia / Adobe
Initial Release
1996
MIME Type
application/x-shockwave-flash

What is an MKV file?

The Matroska Video (MKV) file is an open-standard, free container format capable of holding an unlimited number of video, audio, picture, or subtitle tracks in one file. Unlike proprietary containers, Matroska is structured upon Extensible Binary Meta Language (EBML), allowing for significant flexibility and forward compatibility. It supports a vast array of codecs, including H.264, VP9, HEVC, AAC, Vorbis, and FLAC, and is particularly noted for its support of soft subtitles (SSA/ASS) and chapter entries, making it a standard for high-definition video distribution (HD) and anime fansubs.

How to open an MKV file

Native support for MKV is available in Windows 10/11 via the Movies & TV app and generally on Linux distributions. macOS requires third-party software, as QuickTime Player does not natively parse the Matroska container. The industry-standard solution for all operating systems is VLC Media Player, which includes built-in libraries for decoding the diverse codecs often encapsulated within MKV files. Alternative options include MPV and MPC-HC (Windows).

MKV Technical Info

Full Name
Matroska Video Container
Developed By
Matroska (non-profit)
Initial Release
2002
MIME Type
video/x-matroska

Why RunConvert

The fastest way to convert any file

Purpose-built for speed, privacy, and breadth of format support.

Convert SWF to MKV in seconds

Every SWF to MKV conversion runs on our servers, so your device stays fast and the output quality stays intact.

Fast, cloud-powered

No queue, no waiting. Files are processed on high-performance servers and returned in seconds, even for large files.

Secure & private

Encrypted in transit and never shared with anyone. Uploads are erased the moment your job completes, and results shortly after.

Free - no account needed

Convert without creating an account - no credit card, no trial clock. Sign in only if you want history and higher daily limits.

Developer API

Convert SWF to MKV via API

Automate SWF to MKV conversions in three steps: create a job, upload your file, then poll for the result.

# 1. Create job
curl -X POST https://api.runconvert.com/v3/jobs \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "tag": "swf-to-mkv",
    "tasks": {
      "upload-file": {
        "operation": "import/upload"
      },
      "convert": {
        "operation": "convert",
        "input": "upload-file",
        "output_format": "mkv"
      },
      "export-result": {
        "operation": "export/url",
        "input": "convert"
      }
    }
  }'

# 2. Upload your file (use upload_url from the response)
curl -X PUT "$UPLOAD_URL" --upload-file input.swf

# 3. Poll for result
curl https://api.runconvert.com/v3/jobs/$JOB_ID?include=tasks \
  -H "Authorization: Bearer YOUR_API_KEY"

Replace YOUR_API_KEY with your RunConvert API key. Get your free API key at runconvert.com/api.