Choose Constant Quality when you care about the picture and can accept a variable file size. Choose Average Bitrate when you must work within a size budget, then account for audio and overhead and measure the finished file. Neither option promises a universally “best” setting or makes a compressed viewing copy a replacement for your archive source.
This guide starts with readable video from your own or authorized media. For the preceding container and playback choices, use the Blu-ray to MP4 compatibility workflow.
Decide which constraint matters
| Your requirement | Starting choice | What remains to verify |
|---|---|---|
| Keep a satisfactory picture without a strict size limit | Constant Quality (CQ/RF) | Representative scenes and the complete output size |
| Fit an upload or delivery limit | Average Bitrate (ABR), with multi-pass where supported | All tracks, overhead, actual bytes and acceptable picture quality |
| Preserve the only archive source | Keep that source separately | Neither rate-control mode is a substitute for an archive copy |
| Meet a playback client’s limits | Establish a compatible preset first | Codec, resolution, profile, audio, subtitles and real playback |
ABR controls the average video bitrate, not an identical bitrate for every frame. The video setting is also not the total file bitrate: separate audio tracks and container data still occupy space. CQ instead sets a quality target and lets bitrate vary with the material. HandBrake’s CQ/ABR technical page explains that distinction, but labels itself a draft; its older RF recommendations are not used here.
Read RF in the context of the encoder
HandBrake’s current Adjusting quality guide gives RF 20–24 as a starting range for 1080p with x264 or x265. These are the named encoders, not every implementation of H.264 or H.265. Start with your selected preset, then compare small changes on the same source.
For x264 and x265, a lower RF number asks for higher quality and generally more space; a higher number asks for lower quality. Do not transfer the number unchanged to another encoder and assume equal quality. HandBrake explicitly warns that x264, x265 and SVT-AV1 scales are not comparable, and that some encoders, including Apple VideoToolbox, use the opposite numeric direction.
The reference range is not a promise of transparency, compatibility or a particular size. If an output is much larger than expected, check the encoder, quality setting and selected tracks before changing anything. Reducing the RF number in x264 to “make it smaller” moves the quality target in the wrong direction.
Budget a hard file-size limit
For a known duration, start from a byte budget and subtract the average bitrate of every output audio track. Reserve space for subtitles, container data and uncertainty rather than assigning the entire limit to video.
Video budget (kbit/s)
= media budget in bytes × 8 ÷ duration in seconds ÷ 1000
− sum of audio bitrates in kbit/sThis is unit arithmetic, not a HandBrake size guarantee. Here is one worked example:
| Assumption | Value |
|---|---|
| Full duration | 120 minutes = 7200 seconds |
| Hard file limit | 2,000,000,000 bytes (decimal 2 GB, not 2 GiB) |
| Budget assigned to video and audio | 1,900,000,000 bytes |
| One output audio track’s assumed average | 256 kbit/s |
| Calculated video allowance | About 1855.11 kbit/s |
| Example rounded-down video setting | 1850 kbit/s |
At those assumed averages, video plus audio occupies 1,895,400,000 bytes before overhead. The initial 100 MB reserve is an illustration, not a recommended universal overhead percentage. Actual audio bitrate, passthrough tracks, extra streams and encoder behavior can change the result. Inspect the complete file’s byte count before submitting it; leave more room if your inputs are uncertain.
HandBrake’s CLI reference distinguishes video bitrate in kbit/s, per-track audio bitrate, quality and multi-pass options. Check the selected encoder’s available controls in your installed version. Use multi-pass for an ABR job where it is supported; do not assume every hardware encoder offers the same options or takes a fixed amount of time.
If the calculated budget produces unacceptable pictures, revisit the size constraint, duration or access-copy resolution. Do not describe the chosen number as a recommended Blu-ray bitrate. See the audio and subtitle retention checklist before removing tracks just to meet a limit.
Compare settings without changing everything at once
- Record the HandBrake version, source, encoder, preset, resolution, filters, frame-rate settings and output tracks. Keep the original available.
- Select several relevant scenes, such as motion, dark gradients, fine texture and a subtitle event. A quiet dialogue shot alone is a weak comparison for a varied recording.
- Use HandBrake’s Preview feature to encode a short section. Keep the other settings fixed while comparing RF values or a budgeted ABR setting.
- Watch the results on the intended client and check artifacts, audio and subtitle behavior. Record why a candidate passes or fails.
- Encode the full program, measure its actual bytes, and check duration and tracks. Use the backup-file verification workflow for the separate integrity checks.
A preview checks only the section encoded. Multiplying a CQ sample’s size by the full duration is not a dependable size forecast when scene complexity changes. For a whole library, measure representative completed files before using the storage-planning worksheet.
What was checked
We reviewed the linked HandBrake documentation on October 26, 2026 and independently checked the arithmetic above. We did not run HandBrake encodes or test physical discs, drives or playback devices for this article. The example does not establish compression efficiency, picture quality or a success rate. Keep the verified source and treat any compressed output as a separately evaluated viewing copy.