SWF to HEVC Converter

Convert SWF to HEVC

This tool renders an old SWF (Adobe Flash) movie on our servers and re-encodes the resulting frames into a .hevc H.265 file — pushing a 1996 vector format into a 2013 codec. Two facts about that output decide whether this is the right page for you, so read them first. The .hevc file is actually a Matroska (MKV) container carrying the H.265 video, so MKV-capable players such as VLC 3.0+ and mpv open it directly — but QuickTime, stock phone galleries, and many editors do not support Matroska, and the unusual extension confuses software that goes by file name (renaming to .mkv helps). And any soundtrack the SWF carried is preserved, re-encoded to AAC by default. If you want a modernised Flash clip that plays in stock apps everywhere, MP4 is the friendlier wrapper — see SWF to MP4 below.

SWF Format at a Glance

HEVC (.hevc) Format at a Glance

How to Convert SWF to HEVC

1. Upload Your SWF File: Drag and drop the .swf onto the page or click "+ Add Files" to browse. You can queue several SWF files and convert them together.
2. Pick a Quality Preset: Open Advanced Options. The output codec is fixed to H.265, and the "Preset" under "File Compression" sets the encode quality — it defaults to "Very High (Recommended)". Because the SWF is rendered and fully re-encoded, this preset, not the source, sets the output quality.
3. Set Resolution or Trim (Optional): Use "Video resolution" to keep the original size or pick a preset, "Specific file size" to aim at a byte target, or "Trim" with a "Time Range" to export one section.
4. Convert and Download: Click "Convert" and download your .hevc file. No sign-up, no watermark.

Frequently Asked Questions

Why won't my .hevc file play in QuickTime or on my phone?

Two reasons. The .hevc file is a Matroska (MKV) container, and QuickTime, the Windows Photos app, phone galleries, and browsers generally do not support Matroska — and the unusual extension trips up software that picks a player by file name (renaming the file to .mkv fixes that part). VLC 3.0+ and mpv open it directly, audio and seeking included, because it is ordinary Matroska. If a device or app insists on MP4, remux it losslessly (for example with FFmpeg, ffmpeg -i input.hevc -c copy out.mp4) or convert to SWF to MP4 in the first place.

Does the HEVC output keep the SWF's audio?

Yes. A SWF can embed an MP3 or ADPCM soundtrack, and because the .hevc output is a Matroska container, that sound is carried over — re-encoded to AAC by default, with AC3, MP3, and Opus selectable under Audio Codec. The caveat is playback reach, not the audio itself: Matroska does not open in stock Apple or phone apps, so if the clip is meant for sharing, SWF to MP4 keeps both the video and the sound in a wrapper that plays far more widely.

Why is my HEVC video blank or missing parts of the animation?

SWF is an interactive vector container, not a flat video. Rendering works well for timeline-animated content — banners, intros, cutscenes — but script-driven SWFs (games, menus, dynamically loaded assets) build their visuals at runtime through ActionScript and may render incompletely or blank, since a passive render cannot drive that logic. The first moments are also often just a background or pre-loader. For content that only appears after interaction, a desktop Flash emulator such as Ruffle lets you play the file and capture it yourself.

Will converting to H.265 make my old Flash clip look sharper?

No. H.265/HEVC was approved by the ITU-T and ISO/IEC in 2013 and reaches roughly the same quality as H.264 at about half the bitrate, so it compresses efficiently — but it cannot add detail the source never had. SWF artwork is largely vector and resolution-independent, so it is rasterized at whatever size you set under "Video resolution"; for crisp lines, render at a high preset rather than expecting the codec to invent sharpness. H.265 carries the rendered image forward efficiently; it does not enhance it.

Is converting SWF to HEVC lossless?

No. The SWF is rendered to frames and those frames are encoded with the H.265 encoder — a full generation of lossy compression, not a copy. The vector source is also rasterized to a fixed pixel grid in the process, so the result is a raster derivative of resolution-independent art. Keep the original .swf as your master and treat the .hevc as a derived artefact. To limit the loss, encode at a high "Preset" and render at a generous resolution.

What frame rate does the HEVC output use?

The render follows the frame rate declared in the SWF's header — Flash movies store a nominal frames-per-second value that the timeline plays back at, so animation authored at 24 or 30 fps carries that cadence into the encoded stream. Script-driven motion that ran faster or slower than the header rate at runtime will not be reproduced, since a passive render cannot drive ActionScript timing.

Is the HEVC output 8-bit SDR, or can it carry 10-bit HDR?

It is 8-bit standard-dynamic-range. The H.265 codec supports 10-bit and HDR, but the SWF source is 8-bit sRGB vector-and-bitmap artwork with no HDR information, so there is nothing extra to encode. Rendering at a higher preset or resolution improves sharpness; it cannot add color depth the source never had.

Does the HEVC keep any of the SWF's interactivity or buttons?

No. The output is passive video — a flat sequence of rendered frames. Clickable buttons, menus, and any ActionScript behavior are lost, because a video file has no way to carry interactive logic. To keep the file interactive, play the original in a Flash emulator such as Ruffle rather than converting it to video.

How are my files handled during conversion?

Despite what the extension implies, the .hevc output from this converter is a normal Matroska container — H.265 video plus the SWF's soundtrack as AAC — so MKV-capable players open it directly. Your file is uploaded over an encrypted connection, rendered and re-encoded on our servers, and deleted automatically a few hours after conversion — no sign-up, no watermark, never shared or made public. The main practical limit is upload size and time, not your device.