What bitrate should I use for video?

“Bitrate” is the number people reach for first when they want a smaller file, and it is also the number most likely to be set wrong. The trouble is not that the concept is hard. It is that there is no single correct bitrate for a given resolution. The right number depends on the content, the codec, and where the file is going. This guide gives you the background to pick sensibly and the ranges that work in practice for H.264.

What bitrate actually is

Bitrate is the number of bits the encoder spends per second of video, usually measured in kilobits per second (kbps) or megabits per second (Mbps). Multiply it by the duration and you get a rough idea of the file size: a 5-minute clip at 5 Mbps is around 1.9 GB before audio and container overhead.

Two encoding modes use bitrate differently:

• CBR (Constant Bitrate) spends the same number of bits every second regardless of what is on screen. Predictable size, but wasteful on simple scenes and starved on busy ones.
• VBR (Variable Bitrate) spends more bits where the picture needs them and fewer where it does not. Same average size, better quality, which is why VBR is the usual pick.

There is a third mode, CRF (Constant Rate Factor), that does not target a bitrate at all. You tell the encoder how much quality to keep and it spends whatever bits each scene needs. CRF is what the DivXpress slider actually uses, because for “make it smaller without wrecking it” it is the most reliable knob. The how compression works guide covers CRF in more detail.

Why one bitrate does not fit all

A common mistake is to ask for “the bitrate for 1080p” as if the resolution alone fixes the answer. It does not, for two reasons.

First, content drives bitrate more than resolution. A locked-off interview at 1080p compresses cleanly at 3 to 4 Mbps. The same resolution of a basketball game, with motion filling every frame, can need 8 to 10 Mbps to avoid smearing. The talking-head shot is mostly identical from frame to frame, so the encoder has very little new information to store. The sports clip changes almost everywhere, so it needs far more bits to look clean.

Second, the codec changes the math. H.265 (HEVC) and AV1 deliver similar quality to H.264 at substantially lower bitrates. The numbers below are for H.264 specifically. If you are working in HEVC, you can roughly halve them and land in the right area.

Published H.264 ranges that work

Rather than inventing numbers, it helps to lean on the recommended bitrates that major platforms publish for their own uploads. These are well-tested starting points for H.264 SDR content meant for typical web viewing:

Resolution	Typical H.264 bitrate	Good for
480p	2.5 to 4 Mbps	Talking heads, screen recordings, casual sharing
720p	5 to 7.5 Mbps	Everyday web video, most social clips
1080p	8 to 12 Mbps	Standard HD for YouTube-style uploads
1440p	16 to 24 Mbps	Higher-detail HD
4K	35 to 45 Mbps	High-detail HDR and large-screen viewing

Treat these as starting points, not commandments. Within a resolution, push toward the low end for simple footage (interviews, slideshows, screen recordings) and toward the high end for complex footage (sports, foliage, fast camera motion, confetti).

Audio bitrate, briefly

Audio is a small share of the file, but it is worth getting right. For AAC, the standard codec inside an MP4:

• 96 to 128 kbps is plenty for voice and casual content.
• 160 kbps is a good default for general use, and is what the DivXpress MP4 encoder uses.
• 256 kbps and up is for music you care about preserving.

Going above 192 kbps for spoken content buys you almost nothing. Below 96 kbps, voice starts to sound thin.

Two pitfalls to avoid

Pitfall one: targeting a bitrate that is too high for the resolution. A 1080p clip does not automatically need 20 Mbps. Cranking the bitrate past what the picture can use just produces a larger file with no visible improvement, because the extra bits have nothing meaningful to encode.

Pitfall two: chasing bitrate when you should use CRF. If your goal is “smaller but still looks fine,” picking a target bitrate is the hard way to get there. CRF lets you set a quality target and let the encoder choose the bitrate per scene, which is exactly what most people actually want.

How this maps to DivXpress

DivXpress encodes MP4 and MOV output as H.264 with AAC audio. Rather than asking you to type a bitrate, the quality slider sets a CRF value and lets the encoder find the bitrate each scene needs. If you want to aim at one of the ranges above, the practical move is to encode, check the resulting bitrate in the output metadata, and nudge the slider until you land where you want.

For clips headed to email or messaging, where the goal is fitting under a size limit rather than hitting a quality bar, the shrink a video for email and social guide walks through the right order of operations.

The short version

• Bitrate is bits per second, and it is the real size dial.
• Content drives bitrate more than resolution does. Simple footage compresses far smaller than complex footage at the same quality.
• For H.264, the published platform recommendations (around 8 Mbps for 1080p, 5 Mbps for 720p) are solid starting points.
• For “smaller but still fine,” CRF is usually a better choice than picking a target bitrate.
• Audio at 128 to 160 kbps AAC covers most everyday use.

The compress-video tool uses CRF under the hood, so you get the simplicity of a single slider with the per-scene efficiency of variable bitrate, all without uploading your file.