Knowing these details before you commit to editing, uploading or converting a file saves real time. A video that turns out to be 480p rather than the 1080p the filename implies, a clip with no audio track at all, or a file whose duration does not match what a project timeline expects are all things worth catching before they cause a problem three steps later in a workflow.
Nothing about the file leaves your device. The browser's own media pipeline decodes just enough of the file to report its metadata, so a private recording or an unreleased edit never has to be uploaded anywhere just to check its basic details.
What a video metadata viewer can and cannot tell you
Browsers expose a solid, dependable set of details through the standard HTMLVideoElement interface: exact duration in seconds, the pixel width and height the video decodes to, and whether the browser considers the file playable at all. This tool reads all of that directly and presents it immediately once the file loads.
Some details that video editing software shows, such as the exact codec name, the container's internal frame rate or the audio sample rate, are not reliably exposed to web pages by any browser. Rather than guessing at those figures or fabricating a plausible sounding number, this viewer either omits them or clearly labels them as an estimate, since an inspection tool that quietly makes numbers up is worse than one that says a figure is not available.
- Use a video metadata viewer to confirm the real pixel dimensions of a file before publishing or embedding it.
- Check duration against what a project timeline or a platform's length limit expects.
- Confirm whether an audio track is present before assuming a silent preview means a broken file.
- Treat the estimated bitrate as a rough figure based on file size and duration, not an exact encoder value.
Reading dimensions, aspect ratio and duration
Pixel width and height come straight from the video element once its metadata has loaded, and they reflect the actual decoded frame size, not a value read from a filename or a container tag that could be wrong or stale. The aspect ratio shown is calculated directly from that width and height, which is the most reliable way to identify whether a file is genuinely widescreen, square or portrait orientation regardless of what a video was originally intended to be.
Duration is reported to a tenth of a second, taken from the same metadata the browser uses to draw a video's seek bar, so it matches what any player showing the file would display. A duration of zero or a value that never resolves usually means the browser could not fully parse the file, which is itself useful diagnostic information.
Estimated bitrate and audio track detection
Bitrate is calculated by dividing the file's total size in bits by its duration in seconds, which produces an average across the whole file rather than the exact encoder setting used. A file with variable bitrate encoding, common in most modern video, will show higher and lower moments than this single average figure suggests, so treat it as a useful ballpark rather than a precise measurement.
Detecting whether an audio track exists relies on browser specific properties that are not standardised the same way across every browser, so this viewer reports what it can determine and says plainly when a browser does not expose that information rather than assuming silence means no audio track exists.
This video metadata viewer reads metadata only, it never touches a single frame
The file is loaded into a standard HTMLVideoElement with its source set to a local object URL created from the selected file, and the browser's own video pipeline handles parsing enough of the container to expose duration and dimensions through the loadedmetadata event. No frames are drawn to a canvas and no MediaRecorder is involved, since reading metadata does not require decoding or re encoding any actual video frames.
Because loadedmetadata fires from a local object URL rather than a remote source, the entire lookup completes as soon as the browser has parsed enough of the container's header to know its duration and frame size, which is why the numbers usually appear well before the file would have finished uploading to anywhere else.
How to check video file metadata
- 1
Add your video file
Drag a video file onto the drop area, or click it to browse. MP4, WebM and MOV are all accepted.
- 2
Wait for metadata to load
The browser reads duration and dimensions from the file within a second or two of it being selected.
- 3
Review the reported details
Duration, pixel dimensions, aspect ratio, file size, estimated bitrate and audio track presence are all shown together.
- 4
Check a different file
Choose another file at any time to inspect it the same way, without reloading the page.
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Sources and further reading
Frequently asked questions
Common questions about the video metadata viewer.
Certain WebM files store their duration in a way some browsers cannot resolve until they have scanned further into the file than just the header, so the video element briefly reports an unresolved value before correcting itself. If the figure never settles, seeking once to near the end of the file usually forces the browser to compute the real duration.
Not reliably. Browsers do not expose a standardised way to read the exact codec name of an arbitrary video file from a web page, so this viewer focuses on the details that are reliably available, such as duration and pixel dimensions, rather than guessing at a codec name it cannot confirm.
It is a rough average calculated from the file's total size divided by its duration, not a figure read from the encoder's actual settings. Video encoded with a variable bitrate will have moments well above and below this single reported average, so treat it as a general indicator rather than an exact value.
Browsers differ in whether and how they expose the presence of an audio track to a web page, and no single standardised property works reliably everywhere. When a browser does not expose that information, this viewer says so plainly rather than assuming a track is missing when it might simply be undetectable in that browser.
Any format your browser can decode for playback, which typically includes MP4 with H.264 or H.265 video, WebM with VP8 or VP9, and QuickTime MOV files, though exact support varies by browser and operating system. If a file fails to load, the browser itself cannot decode that particular codec or container.
No. This is a read only inspection tool. It only loads the file into a video element to read its metadata and never draws frames to a canvas, re encodes anything or produces any output file at all.
Yes. This page acts as both a video dimensions checker and a video duration checker at once, reading the exact decoded width, height and duration directly from the browser's video element rather than estimating them from a filename or a container tag that could be wrong.
Yes. You can check video file info and inspect video file online at no cost, with no sign up and no software to install. Every reported detail, from duration to dimensions, appears within moments of dropping in a file, and nothing is uploaded to make that possible.