Video Resolution Checker
Find out exactly what is inside a video file: its resolution and quality class, aspect ratio, length, frame rate, bitrate, container and the video and audio codecs. Check one file or a whole batch, without uploading anything.
How to use the Video Resolution Checker
- Choose one or more videos by dropping them into the box or clicking to browse.
- Wait a moment while the tool reads the file header and plays a second of video in the background to measure the frame rate.
- Read the summary cards: resolution, duration, frame rate and bitrate.
- Check the details in the Video, Audio and File tables, such as codecs, aspect ratio and sample rate.
- Press Download report (CSV) to save the results for all files, or Copy report to paste them elsewhere.
Common video resolutions
| Name | Landscape size | Portrait (phone) size | Megapixels | Typical bitrate (30 fps) |
|---|---|---|---|---|
| 480p SD | 854 × 480 | 480 × 854 | 0.41 | 1–2.5 Mbps |
| 720p HD | 1280 × 720 | 720 × 1280 | 0.92 | 2.5–5 Mbps |
| 1080p Full HD | 1920 × 1080 | 1080 × 1920 | 2.07 | 5–10 Mbps |
| 1440p QHD | 2560 × 1440 | 1440 × 2560 | 3.69 | 10–16 Mbps |
| 4K UHD | 3840 × 2160 | 2160 × 3840 | 8.29 | 20–45 Mbps |
| 8K UHD | 7680 × 4320 | 4320 × 7680 | 33.18 | 50–100 Mbps |
The quality class is based on the shorter side of the picture, so a vertical 1080 × 1920 phone video counts as 1080p, just like a 1920 × 1080 landscape video. Cinema-style files such as 1920 × 800 still count as 1080p because of their width.
Formulas used
- Aspect ratio = width : height, reduced by their greatest common divisor. 1920 × 1080 → divide both by 120 → 16:9. 320 × 240 → divide by 80 → 4:3.
- Overall bitrate = file size × 8 ÷ duration. A 75 MB (78,643,200 bytes) clip lasting 60 s → 78,643,200 × 8 ÷ 60 ≈ 10.5 Mbps.
- Frame rate from the header: in WebM, fps = 1,000,000,000 ÷ DefaultDuration (in nanoseconds), so 40,000,000 ns gives 25 fps. In MP4, fps = timescale × sample count ÷ total sample duration.
- Frame count ≈ frame rate × duration, for example 29.97 × 120 s ≈ 3,596 frames.
Containers and codecs explained
A video file is a container (MP4, MOV, WebM, MKV) that holds separately compressed video and audio streams. The container decides which streams are allowed; the codec decides how the picture and sound are compressed. MP4 usually carries H.264 or H.265 video with AAC audio, WebM carries VP8, VP9 or AV1 with Opus or Vorbis, and MKV can hold almost anything. If a video won't play somewhere, the codec, not the file extension, is usually the reason, so check it here before converting.
Frequently asked questions
How do I check the resolution of a video?
Drop the video into the box above. The tool shows its width and height in pixels, for example 1920 × 1080, together with its quality class (1080p Full HD), aspect ratio and orientation.
How is the frame rate found?
For MP4, MOV and WebM files the tool first reads the frame timing stored in the file header. If the header doesn't contain it, the tool plays a short, silent part of the video and measures the time between decoded frames with the browser's video frame callback.
What does the bitrate tell me?
The overall bitrate is the file size in bits divided by the duration, including both video and audio. A higher bitrate usually means better quality at the same resolution. For example, 1080p video from a phone is typically 10 to 20 Mbps, while a streamed 1080p video is often 4 to 8 Mbps.
Why does it say my browser can't decode the video?
Some codecs, like H.265 (HEVC) or ProRes, aren't supported by every browser. The tool still reads the resolution, codecs and frame rate from the file header, but it can't show a preview or measure the frame rate by playing it.
What is fast start?
In an MP4 or MOV file, the index (moov box) can sit at the start or the end of the file. With the index at the start, a web player can begin playing before the whole file has downloaded, which is recommended for videos on websites.
Are my videos uploaded?
No. The file is read directly on your device: only the header bytes are parsed, and the short frame-rate test runs in your browser. Nothing is sent to a server, so large and private videos are fine.