Why does my exported video look softer than the preview?

Start by comparing three things: the properties of the original footage, the project’s resolution, and the export’s resolution and quality settings. Then review the exported file itself rather than relying only on the editor preview. In iMovie for Mac, project resolution is based on the first clip added to the timeline, so check whether that project property matches what you expect from the source and export. A difference is a clue to investigate, not proof that it caused the softness. [S1]

For the independent review, choose a representative frame with fine detail, such as hair, foliage, or small text. Open the exported file in a player, pause on that frame, and compare it with the editor view at a similar on-screen size. Also watch a few seconds around it: a single paused frame may not reflect how the whole export looks.

Make a small comparison note before changing anything. Record the source clip’s listed dimensions and frame rate if your editor or file information displays them, the project resolution shown by the editor, and the resolution selected for export. Keep the values as displayed; do not assume that a larger number in one place automatically explains a softer image.

If you use iMovie for Mac, its project settings show the project resolution, which is based on the first clip added to the timeline. That is a useful property to compare, but Apple’s documentation does not say that a mismatch necessarily causes softness. [S1] If the project has multiple clips, note which clip was added first and whether it is representative of the footage you are trying to assess. This is a comparison step, not a diagnosis.

Before exporting again, note the current output resolution and quality choice so you can compare like with like. In iMovie for Mac, the file-export dialog offers resolution and quality options, including Custom quality with a target-bitrate slider; the estimated file size changes as that slider moves. Inspect those settings alongside the source and project properties. [S2]

If you adjust an option, change one setting at a time and export a short representative section if your editor allows it. Give the new file a distinct name, then open that file independently and compare the same detailed frame and nearby motion. Record what you changed and what you observed. A larger estimated file size or a different setting does not, by itself, establish that the image will look sharper; the cited documentation lists controls but does not diagnose every cause of softness. [S2]

Copy this into a note and fill in the values your editor shows:

Source clip: [listed properties] Project resolution: [value shown] Export resolution: [selected value] Export quality: [setting; custom slider value if shown] Test frame or time: [description or timecode] Independent playback observation: [what looks soft, and where] One change tested: [setting changed, or none] Result compared with: [previous export filename]

If the file still looks soft, use the notes to localize the question: does the source already look soft, does the project property differ from the source, or does softness appear only in the independently reviewed export? Recheck that you opened the newly rendered file, not the earlier version. If the evidence remains unclear, consult the current documentation for your specific editor and describe the source, project, export choices, and comparison you made. The cited Apple pages apply to iMovie for Mac; they do not establish causes for every editor or workflow. [S1] [S2]