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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 Black) is only visible 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. Pick White for printed-photo slideshows, 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. Pick Target File Size (%) or Specific File Size if you need to hit a strict cap for an upload. 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 onto the Background Color. VP9 has an experimental alpha profile and FFV1 supports alpha, but most players ignore alpha in MKV. If preserving transparency matters, keep the source as animated WebP or use a WebM with VP9-alpha instead.
Yes. Conversion runs on our servers; WebPs are uploaded to convert, the resulting MKV is delivered to you, and temporary files are deleted after the job completes. No account is needed and no watermark is added.