Where a 25MB limit comes from
Email is a common source of this exact number: Gmail, for example, caps attachments at 25 MB, and because attachments are base64 encoded, a file that looks fine on disk can still be rejected at send time. See the email-specific walkthrough linked below for that detail. Outside email, 25 MB is a reasonable target to start from, not a specific platform's stated limit, so check the current number for wherever the file is actually going.
What to expect at this target
In testing, a short animated clip and a short live-action clip both reached a 25 MB target in a single attempt (see the measured results below). Longer recordings or native 4K footage need a much lower bitrate to fit the same 25 MB target, which affects visible quality more; trimming the clip or choosing a higher target size addresses that more directly than adjusting settings by hand would.
How QuickCompress handles it
Enter 25 in the target-size field and QuickCompress works out the bitrate needed to land at or under it, then encodes locally on your Mac using Apple Silicon hardware acceleration. Your original file stays exactly as it was; the compressed version is a new, separate file.
Formats and where processing happens
MP4 and MOV files go in, a compressed MP4 comes out. Because compression happens on your Mac rather than through an upload to a server, there is no file waiting in a queue somewhere else, though QuickCompress does need the internet the first time you activate your license and when it checks for updates.
Measured result
In the target-size accuracy test, a real animated clip hit 22.84 MB against a 25 MB target (91.4% of target), and a separate live-action clip hit 23.59 MB (94.4% of target), both in a single attempt. A much larger native-4K source in the same test series was not able to reach a 25 MB target at all, landing at 76.94 MB after four attempts, which is why source length and resolution matter more than the target number itself.
Frequently asked questions
Will a 25MB target always look as good as the original?
No. Compression always trades some quality for size, and how much depends on the source: a short clip at a normal resolution keeps more detail at 25 MB than a long or very high-resolution one.