BMP to MKV Converter

Convert BMP to MKV: What You Actually Get

This is a still-to-video conversion, so it is worth being precise about the output before you run it. A .bmp holds one static picture; Matroska (.mkv) is a video container. The converter therefore encodes your bitmap as a video frame and holds it on screen for a length you choose, producing a silent clip with no motion — a picture in a video wrapper. Upload several bitmaps and you get the one thing this page can genuinely animate: a fixed-interval slideshow, one image after another.

How to Convert BMP to MKV

1. Upload Your BMP File: Drag bitmaps onto the page or click "+ Add Files". Upload order is the order they will appear in a merged clip, so add them in the sequence you want.
2. Set the Duration: Under Image Duration, the Duration dropdown decides how long each picture is held — from a single frame at 1/60s up to 10 seconds per frame, preselected on "5 seconds per frame".
3. Check Merge Strategy, Background and Resolution: Merge strategy starts on Merge images, joining every upload into one MKV; Video per image produces one file per bitmap instead. Background Color (White by default) fills any frame area the picture does not cover, and Video resolution starts on "Keep original".
4. Convert and Download: Click "Convert" and save the .mkv. No sign-up, no watermark. Files are uploaded over an encrypted connection, converted on our servers, and deleted automatically after a few hours.

Walk-through: Turning a Folder of Bitmaps into One Clip

Merge strategy is the control that changes the shape of the job, and it starts on Merge images — so if you drop twelve screen captures in and press Convert, you get one MKV containing all twelve, each held for the Duration you set, in upload order. There are no cross-fades, pans or transitions; frames simply cut from one to the next. That is a legitimate output for a contact sheet, a build-progress reel or a set of scanned pages, and it is the only form of motion a still-image source can produce.

Switch to Video per image when the files are unrelated — a batch of individual slates or placeholders, each needing to stand alone. The Duration then applies to each output separately, so twelve bitmaps at five seconds give you twelve five-second clips rather than one long one.

Two things stay constant no matter how you set those controls. The clip is silent, because a bitmap carries no audio for the encoder to work with. And the file-size and bitrate targeting modes you would normally see under File Compression are absent here, because size targeting needs a source bitrate and runtime to reason about, and a still image has neither — which leaves Quality Preset, preselected on "Very High (Recommended)", as the practical size control.

MKV, MP4 or WebM for a Still-Image Clip?

Common Errors and How to Fix Them

• "The video doesn't move" — Expected. Motion requires frames that differ; one bitmap is one frame. Upload several different bitmaps with Merge images for a slideshow, which is as close to motion as a still source gets.
• "There is no audio" — Also expected. A bitmap stores pixels only, so there is nothing to encode into a sound track. Add music or narration afterwards in a video editor.
• "I uploaded ten bitmaps and got one file" — That is Merge images, the preselected strategy. Switch to Video per image for separate outputs.
• "There are white bars around my picture" — The chosen frame size does not match the bitmap's aspect ratio, so the leftover area is painted with Background Color. Set Video resolution back to "Keep original", or change the colour if bars are unavoidable.
• "My TV or phone won't open the MKV" — Matroska is not universally supported on consumer playback devices. Convert the bitmap to BMP to MP4 instead, or run the finished file through MKV to MP4.
• "The frames go by in the wrong order" — Merged clips follow upload order. Remove the files, re-add them in sequence, and convert again.

When This Doesn't Work

If the real goal is a smaller or more portable picture, MKV is the wrong target entirely — wrapping a still in a video container adds overhead and takes away everything that makes an image file convenient. BMP to PNG keeps every pixel and is far smaller than the bitmap; BMP to JPG is smaller still for photographic content. Matroska earns its place only when something downstream genuinely wants a video file: a media server that indexes MKV, an editing or archival pipeline standardised on it, or a slate that has to sit alongside other Matroska assets. And if you were hoping for pans, zooms or cross-fades between images, that is editing work — a format conversion cannot invent camera moves.

Frequently Asked Questions

Why is my BMP to MKV output a frozen picture with no sound?

Because a bitmap is a single static image with no audio track and no second frame. The conversion holds that one picture for the Duration you set, so the clip has a runtime and plays normally, but nothing inside it changes. With several different bitmaps and Merge images selected you get a cutting slideshow instead — still no in-frame movement, just one picture replaced by the next.

How long will the finished MKV be?

Per-image duration multiplied by the number of images, when they are merged. The Duration dropdown runs from a single frame at 1/60s up to 10 seconds per frame and starts at "5 seconds per frame", so a single bitmap gives a five-second clip and twelve merged bitmaps give roughly a minute. Under Video per image, each output is simply one duration long.

Which video codec does the MKV use?

H.264 is preselected for a Matroska target. Matroska is a container rather than a codec, so the Video Codec list in the advanced options also offers H.265, VP9, AV1, MPEG-4, Theora and several legacy encoders when a specific tool requires one. H.264 is the safe default because virtually every player and editor decodes it.

Why choose MKV over MP4 for a still image?

Only when something downstream asks for Matroska by name. The two containers can hold the same H.264 video, but MKV is favoured in open-source, media-server and archival workflows because it can carry an unlimited number of video, audio, subtitle and attachment tracks, and it was published as an IETF standard, RFC 9559, in October 2024. The trade-off is playback reach: MKV is not part of the HTML5 video baseline and many phones and TVs will not open it.

Can I make a slideshow with transitions between the bitmaps?

Not here. Merge images produces hard cuts at fixed intervals — each picture appears for its full duration and is replaced instantly by the next. Cross-fades, pans and Ken Burns-style moves are timeline effects, which means a video editor. What this page does well is the mechanical part: getting a folder of bitmaps into a single, correctly ordered, fixed-interval clip you can then drop onto that timeline.

Why can't I set a target file size for the MKV?

Because size targeting needs something to scale from — a source bitrate, a duration, a complexity profile — and a still image supplies none of it. For image sources the converter keeps the quality-based compression modes only. In practice Quality Preset and Duration are your two size levers: a lower preset spends fewer bits per frame, and a shorter duration encodes fewer frames.

Does upscaling the resolution improve the picture?

No. Selecting a 4K preset stretches the same pixels across a larger frame; it cannot create detail the bitmap never contained, and it makes the file bigger for nothing. Leave Video resolution on "Keep original" unless a downstream tool demands a specific frame size — in which case matching the bitmap's own aspect ratio avoids the background-filled bars.

How are my files handled during conversion?

Your bitmap is uploaded over an encrypted connection, rendered and packaged into Matroska on our servers, and deleted automatically after a few hours. There is no sign-up, no watermark, and files are never shared or made public. Since uncompressed bitmaps are large — a 1920x1080 24-bit BMP holds about 6.2 MB of pixel data — upload size and time is the practical constraint on a big batch.