“Lossless” compression is mostly a myth for video. What’s actually achievable is compression where the quality loss is invisible to the viewer. That’s a realistic goal, and it’s mostly about matching the right settings to the content.
First: understand what “quality” actually means
Quality is not a single number. It depends on:
- Bitrate relative to resolution — a 1Mbps 480p video looks fine; a 1Mbps 4K video looks terrible
- Content type — talking heads compress far better than action scenes or film grain
- Viewing context — a video on a 5-inch phone screen can get away with far less bitrate than the same video on a 55-inch TV
The techniques below reduce file size by working within these variables.
Use the right CRF
CRF 23 (the H.264 default) is a good starting point, but it’s worth testing for your content:
- Animated content: CRF 20–22 often sufficient (low noise = easy to compress)
- Talking heads / screen recordings: CRF 24–26 often fine
- Film grain, sports, high motion: CRF 18–21 needed for acceptable quality
- Archival storage: CRF 17–19
Test by encoding a short clip at CRF 22 and CRF 26, then compare at 100% zoom on your target display. The difference is often invisible at 26.
Strip unnecessary audio channels
Many videos — especially screen recordings and conference calls — have stereo audio with identical content in both channels. Converting to mono halves the audio data. Use the “Compress audio” setting in smaller.video.
Reduce resolution only when it fits your use case
Dropping from 1080p to 720p reduces video data by about 56% (proportional to pixel count: 1920×1080 = 2,073,600 pixels vs 1280×720 = 921,600).
Do this only if the video will be viewed at a size where 720p is sufficient, and you still have the original to re-encode from if needed. Never reduce resolution on footage you plan to edit later.
Cut before you compress
Trim your video before compressing it. Every second of unused footage wastes bits. If your 30-minute recording has 10 minutes of useful content, edit first, then compress.
Choose the right codec for the destination
| Destination | Codec | Why |
|---|---|---|
| Web embedding | VP9 (WebM) | 30–50% more efficient than H.264 at the same quality |
| Email / messaging | H.264 (MP4) | Universal compatibility |
| Apple devices | H.264 (MP4) | Native support everywhere |
| Long-term archive | H.265 (HEVC) | Best compression ratio, widely supported |
If your video will be embedded on a website and your audience uses modern browsers, WebM with VP9 is worth trying.
Use a slower encoder preset
The preset controls how hard the encoder works to find efficient compression. Slower presets produce smaller files at the same quality, at the cost of encoding time.
| Preset | Relative encoding time | File size at same CRF |
|---|---|---|
| ultrafast | 1× | Largest |
| fast | ~3× | Typical |
| medium | ~5× | Smaller |
| slow | ~8× | Noticeably smaller |
| veryslow | ~15× | Smallest |
Going from fast to slow can reduce file size by 10–20% with no quality difference. For a one-off export, that’s usually worth the wait.
Example workflow
Scenario: 45-minute interview, 1080p, 12GB source. Target: under 500MB for web embedding.
- Trim dead air at start and end (assume 40 minutes remain)
- Format: WebM (VP9 — better web compression than H.264)
- Resolution: 720p (talking head; 720p is indistinguishable for this content)
- CRF: 26
- Audio: 96kbps (voice only)
- Preset: slow
Expected result: roughly 150–250MB. Close to 98% size reduction from the source file.
All of these settings are available in smaller.video.