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Supports: WEBP
.webp images. Batch upload is supported, and both static WebP and animated WebP (multi-frame ANMF/ANIM chunks) are accepted.WebP is Google's image format (released 2010), capable of static and animated content using VP8/VP8L compression inside a RIFF container with VP8X, ANIM and ANMF chunks. Matroska (MKV) is an open container that wraps virtually any codec — H.264, H.265/HEVC, VP9, AV1, AAC, Opus, FLAC — plus multiple audio tracks, subtitle tracks, and chapter markers. Turning a folder of WebPs into an MKV gives you a single playable file that home-theater software treats as first-class media.
.zip of WebPs isn't.| Property | WebP (source) | MKV (output) |
|---|---|---|
| Type | Image (RIFF container) | Video container (EBML) |
| Maintained by | Matroska / open spec (CELLAR IETF draft) | |
| Compression | VP8 (lossy) / VP8L (lossless) | Any codec — H.264, H.265, VP9, AV1, FFV1 |
| Animation support | Yes (ANIM + ANMF chunks) | N/A — full video timeline |
| Audio | No | Multiple tracks (AAC, Opus, FLAC, AC3, MP3) |
| Subtitles | No | Multiple tracks (SRT, ASS/SSA, PGS) |
| Chapter markers | No | Yes |
| Browser playback | 95%+ (Chrome 32+, Firefox 65+, Safari 14+ iOS / 16+ desktop) | None natively — desktop players only |
| Max canvas / resolution | 16,383 × 16,383 per frame (24-bit dims) | No spec-imposed cap; codec-limited |
| Choice | When to pick it | Notes |
|---|---|---|
| H.264 + AAC (default) | Universal playback, social uploads | Plays everywhere — VLC, Kodi, Plex, smart TVs, browsers via HTML5 |
| H.265 / HEVC | 4K masters, smaller files | ~40-50% smaller than H.264 at equal quality; needs HEVC-capable player |
| VP9 | Royalty-free 4K | Open codec; Plex transcodes for older clients |
| AV1 | Highest efficiency archives | ~30% smaller than H.265; slow encode but tiny output |
| Lossless (FFV1) | Preservation masters | Bit-exact; large files; pair with the Lossless codec option |
| Very High preset | Default — recommended | Visually transparent for slideshows at typical viewing distance |
| Constant Quality (CRF) | Predictable per-frame quality | Lower CRF = better; 18 visually lossless, 23 default, 28 small file |
There's no source timeline to trim — your input is a stack of images, not an existing clip. Control the slideshow length two ways instead: change the number of WebPs you upload, and adjust Duration (1/60s up to 10 seconds per frame). Total runtime = images × duration.
MKV if the file will live on a Plex, Jellyfin or Kodi server, or you need multiple audio/subtitle tracks. MP4 for phones, web embeds, social uploads, and AirPlay. The same H.264+AAC payload works in either container, so quality is identical — only the wrapper differs. For maximum device reach use WebP to MP4 instead.
Yes. Animated WebP frames (ANMF chunks) are decoded in order and re-timed to the Duration you pick. If the source uses variable per-frame timing, this converter resamples to a fixed frame rate — for most cartoon and meme animations the result is indistinguishable from the original. For a smaller GIF-style output see WebP to GIF.
Upload the frames in filename order, leave Merge images selected, and set Duration to 1/24 second (cinematic 24 fps), 1/30 second (broadcast 30 fps) or 1/60 second (smooth 60 fps). A 1000-frame capture at 1/30s yields a ~33-second 30 fps MKV.
The Background Color (default White) shows in two places: any transparent areas of your WebPs are composited onto it during encoding, and it fills the bars when your WebPs don't match the chosen output aspect ratio — for example, mixing portrait phone shots into a 16:9 1080p timeline produces vertical pillarbox bars. The White default suits printed-photo slideshows; pick Black for cinematic feel, or a brand color for corporate decks.
Most modern smart TVs (LG webOS, Samsung Tizen, Android TV) play H.264-in-MKV directly from USB or DLNA. Chromecast supports H.264 and VP9 in MKV via apps like VLC Mobile and Plex; native Chromecast doesn't accept raw MKV from a browser tab — cast through Plex or a Jellyfin app for full compatibility.
Roughly: minutes × bitrate ÷ 8 = megabytes. The Very High preset targets around 8 Mbps at 1080p, so a 60-second slideshow lands near 60 MB. To land under a strict upload cap, shorten each frame's Duration, pick a smaller resolution, or lower the preset — file-size targeting modes don't appear for image sources. For shrinking an existing MKV afterwards use Compress MKV.
Standard H.264, H.265, VP9 in MKV do not carry alpha — the image is flattened, with transparent areas composited onto the Background Color option (white by default; pick any color from the dropdown), and semi-transparent edges blend smoothly into that color instead of fringing. If preserving transparency matters, keep the source as animated WebP.
Yes. Conversion runs on our servers; WebPs are uploaded to convert, the resulting MKV is delivered to you, and temporary files are deleted automatically after a few hours. No account is needed and no watermark is added.