DropShiftVideo compression
How to compress video on Mac and check its quality
Video compression can help with email attachments, upload limits, and sharing large files. DropShift offers High quality, Balanced, and Smallest size presets and outputs H.264/AAC MP4. Presets control a quality tradeoff rather than an exact target file size, so the reduction varies between source videos.
Before you start: system, permissions, and output folder
This guide uses the direct-download version of DropShift for Apple Silicon (M-series) Macs running macOS 14 or later. Download your source files to your Mac and leave enough disk space for a separate output file.
Drag files into the DropShift window and choose an action; this does not require Accessibility permission. To open the format wheel while dragging in Finder, enable Quick Drag in Settings and grant Accessibility permission, then hold Shift during the drag. Hold Shift + Option during the drag to switch to editing tools.
Results are saved beside the source by default, or in the output folder you choose in Settings. New files do not overwrite originals; an available filename is used when a name already exists. If the source folder is not writable, choose a writable output folder when prompted.
Find a suitable preset with one video first
Check the limit and the source
Check the original file size in Finder and note the receiving platform's limit. Play the source and identify fine text, dark areas, or fast motion where compression artifacts will be easiest to see.
Choose the compression action
Drag the video into the DropShift window and choose compression. With Quick Drag enabled, drag a video in Finder, hold Shift + Option, move to the compression tool, and release the mouse.
Start by comparing Balanced
Select Balanced in the compression window and apply it. If too much detail is lost, try High quality. If the result is still too large, try Smallest size from the original video and check whether the greater detail loss is acceptable.
Check the output, not just completion
Find the MP4 with Compressed in its filename. Compare its byte size and inspect key scenes, audio sync, and duration. Share it after it meets your requirements. Start each preset comparison from the original rather than repeatedly compressing an output.
When to use each preset
| Preset | A useful starting point | What to check |
|---|---|---|
| High quality | Fine detail and text-heavy demonstrations | Whether file size fits the sharing limit |
| Balanced | Everyday sharing and an initial comparison | Text clarity, dark areas, and motion |
| Smallest size | Smaller transfers with more detail loss allowed | Whether blocking, soft edges, and lost detail are acceptable |
None of these presets is lossless, and none guarantees an output smaller than the source. The compression action does not automatically shorten duration or lower resolution, and it does not offer an exact target such as 10 MB or 25 MB.
When the result is still too large or quality is poor
- The source is already compact: a low-bitrate video or efficiently encoded source can grow when re-encoded as H.264. Keep the original and compare actual results instead of repeatedly compressing it.
- A strict attachment limit still is not met: if Smallest size remains too large, trim unneeded footage with the trim tool and check again. Use a tool with explicit bitrate or resolution controls when you need those parameters.
- Fine text softens or motion shows blocking: return to the original and try a higher-quality preset. Keep original footage for later editing or archiving, with sharing copies stored separately.
- Missing sound, subtitles, or other tracks: compression uses the first video stream and first audio stream and does not preserve every audio track or subtitle. Decide which elements the recipient needs before using this workflow.