rendering before output

Sometimes when I am in a hurry I will export a file to Vimeo or YouTube without rendering my timeline and it doesn't seem to effect the quality. I remember a discussion at one point where it was suggested that FCPX will render as it exports. Is that true and if so, is there a strong reason to render before export? thx

Rendering the Timeline doesn't affect the quality of your exported video. You render the Timeline to improve the playback of the Timeline. So the answer is no, you don't need to render before exporting.

FCPX renders your output on export, but it is done much faster (depending on your machine) as the rendering in your timeline.

Thanks. That's what I thought.

Adding to the excellent replies above, just this remark:

When you are working on a long and complex Project with lots of titles and/or effects it may be a good idea to render your Timeline before exporting unless you are absolutely sure that you won't have to make any changes to your Project anymore and you won't have to export the Timeline again. Let me explain.

Some titles and effects can take a long time rendering or exporting. If after exporting an unrendered Timeline you have to make some changes to your Project (even only some audio or video cuts) and export again, every title and effect will have to be recalculated again during the export.

OTOH if you have rendered your Timeline and you have to make some minor changes and export again the export will be much faster as all your titles and effects have already been pre-rendered.

- Ronny