Without knowing specifics, here are some general suggestions:
- Restart Shotcut to get back to the default export option.
- Ensure that Export panel > “Use hardware encoder” is not checked unless you have a 7th-gen NVENC GPU like Nvidia RTX 20xx or higher.
- Hit the Advanced button, go to the Codec tab, and lower the quality percentage until the quality/file size trade-off is acceptable to you.
- If step #3 was not sufficient reduction, go to the Advanced > Other tab, change these lines to say
vprofile=veryfast
andvpre=veryfast
, then repeat quality tests for step #3.
I’m guessing that hardware encoding could be causing the file size problem. Older GPUs frequently produce file sizes that are 3x larger than software encoders for the same quality level.