Key takeaways
- Four numbers describe most of a video file: resolution, frame rate, bitrate and codec.
- Your operating system, VLC, MediaInfo and ffprobe can all show them. You do not need to open an editor.
- Bitrate, not resolution, decides how good a picture looks for a given file size. A 1080p video can look worse than a 720p one.
- You can estimate an unknown bitrate yourself: file size in bits ÷ duration in seconds.
Before you compress, convert or embed a video, it helps to know what is actually inside it. "It is an MP4" tells you very little. Two MP4 files can differ by a factor of ten in size and in quality. This guide shows you how to read a file's details with tools you already have, and what the numbers mean in practice.
What each number means
- Resolution
- The picture's width and height in pixels, such as 1920 × 1080 (called "1080p") or 1280 × 720 ("720p"). Portrait phone clips are the other way round, such as 1080 × 1920.
- Frame rate
- How many pictures are shown per second (fps). Common values are 24 (film), 30 and 60 (smoother motion, used a lot in gameplay).
- Bitrate
- How much data is used per second of video, usually in kilobits per second (kbps) or megabits per second (Mbps). Higher bitrates keep more detail and make bigger files.
- Codec
- How the video and audio are compressed. For video, common codecs are H.264, HEVC (H.265), VP9 and AV1. For audio, AAC and Opus are common.
Windows: File Explorer
- Right-click the file and choose Properties.
- Open the Details tab.
- Look under Video for frame width, frame height, data rate and frame rate, and under Audio for the audio bit rate.
The "data rate" under Video is the video bitrate; "total bitrate" combines video and audio. The Properties dialog does not name the codec. For that, use VLC or MediaInfo.
macOS: Finder and QuickTime
- Select the file in Finder and press Cmd+I (Get Info). Expand More Info to see the dimensions, codecs and duration.
- For more, open the video in QuickTime Player and press Cmd+I to open the Movie Inspector, which lists the format, data rate and frame rate.
VLC (all platforms)
Open the video in VLC, then choose Tools > Codec Information (Ctrl+J on Windows and Linux, Cmd+J on Mac). You will see a stream list showing the video codec, resolution, frame rate and the audio codec and sample rate. The Statistics tab shows the live bitrate while the video plays.
MediaInfo: the most complete graphical view
MediaInfo is a free tool that reports every detail of a media file in a single window: container, codecs and profiles, resolution, frame rate, colour information, bitrate (including whether it is constant or variable) and audio channels. When a video behaves strangely in an editor or on a device, MediaInfo is usually the quickest way to see why.
ffprobe: for scripts and exact answers
If you have ffmpeg installed, ffprobe comes with it. This command prints the essentials for the first video stream:
ffprobe -v error -select_streams v:0 \
-show_entries stream=codec_name,profile,width,height,r_frame_rate,bit_rate \
-of default=nw=1 input.mp4And this prints the duration and overall bitrate for the whole file:
ffprobe -v error -show_entries format=duration,size,bit_rate -of default=nw=1 input.mp4The frame rate appears as a fraction, so 30000/1001 means about 29.97 fps. If bit_rate shows as N/A for the video stream, calculate it yourself using the formula below.
Work out the bitrate from the file size
You can estimate the average bitrate of any file with simple arithmetic:
average_kbps = (file_size_in_MB × 8192) ÷ duration_in_secondsFor example, a 45 MB clip that lasts 60 seconds averages 45 × 8192 ÷ 60 ≈ 6,144 kbps, or about 6 Mbps. This figure includes the audio. If you need to hit a target size, our guide to compressing a video to fit a size limit uses the same formula in reverse.
How to read the results
| What you see | What it usually means |
|---|---|
| 1080p at 1 to 2 Mbps | Heavily compressed. It will look soft or blocky in busy scenes, and a 720p version at the same bitrate would likely look better. |
| 1080p at 6 to 10 Mbps (H.264) | A healthy range for general web video. YouTube's upload guidance suggests around 8 Mbps for 1080p at standard frame rates. |
| Codec shows HEVC or AV1 | Efficient, but some older devices and editors cannot play or import it. Convert to H.264 if you need maximum compatibility. |
| Frame rate of 59.94 or 60 | Smooth motion, but roughly double the data of 30 fps for the same quality. |
| No audio stream listed | The video has no sound. The recording tool never captured audio, or it was removed. |
| Variable frame rate | Common in screen recordings and phone videos. It can cause audio to drift in some editors; convert to a constant frame rate if you see that. |
Why resolution alone is a poor guide to quality
People often judge a video by its resolution label, but the label only says how many pixels there are. The bitrate says how much information was kept about them. A 4K video squeezed into a tiny bitrate can look worse than a well-encoded 720p video. That is also why a downloaded file can look different from the original even when the resolution matches: the bitrate or codec differs.
When a service such as Streamable offers more than one version of a video, our downloader lists each with its resolution and size so you can compare them. The larger file at the same resolution almost always has the higher bitrate and the better picture.
Quick answers
What is a good bitrate for a short clip?
It depends on the resolution and how much motion there is. As a starting point for H.264: 1 to 2.5 Mbps for calm 720p, and 5 to 8 Mbps for busy 1080p. See the table in our compression guide.
Why is my video file so big?
A high bitrate, a long duration, 60 fps, or a professional codec such as ProRes. Check the bitrate first; it is the number that explains the size.
How do I tell if a video is HEVC or H.264?
Open it in VLC (Tools > Codec Information) or MediaInfo. The video stream lists the codec by name.
Need to save a Streamable clip? Paste its link into the free Streamable downloader and get the original MP4 in a few seconds. Only download videos you own or have permission to keep: see our copyright basics guide.