The first question is whether the destination accepts the codec/profile you plan to send. Once the platform is going to transcode the upload, your goal is to give it a clean source with enough quality rather than trying to predict the exact codec viewers will receive.

H.264 remains an excellent upload format because it is broadly supported and easy to decode. HEVC can be useful when upload bandwidth or local storage matters and the platform accepts your file reliably, because you may reach a similar quality target at a lower bitrate.

But do not reduce bitrate too aggressively just because HEVC is more efficient. The platform will compress the video again. Starting with visible blocking, smearing or banding gives the next encoder less clean information to work with.

For either codec, a high-quality source encode is more important than winning a tiny file-size contest before upload.

I would also distinguish “upload master” from “file I send directly to people.”

For a platform upload, you can use a format the service accepts and let it create its delivery versions. For a downloadable file that needs to play on unknown TVs, phones and office PCs, compatibility becomes much more important and H.264 is usually the lower-risk option.

If your internet connection is slow, HEVC can reduce the time spent uploading a high-quality master, but encoding it may take longer. So total turnaround is a combination of encode time + upload time + processing time, not just file size.

That is a good example of why the best codec depends on the bottleneck you actually have.

For HDR/10-bit work, check the whole delivery chain rather than only H.264 versus H.265.

The source color space, transfer function, metadata and bit depth need to match what you intend to upload. An HEVC file can be technically efficient but still look wrong if HDR footage is tagged or transformed incorrectly. Conversely, an SDR H.264 file can look excellent if the tone mapping and grading were handled properly.

Before a long upload, render a short representative section that includes highlights, shadows, gradients and fast motion. Play it locally, inspect the file information, and upload it privately/unlisted if the platform supports that workflow. Confirm the processed result before committing hours to the full export.

For most conventional SDR uploads, H.264 is still a very practical default because it combines good quality with very broad compatibility. HEVC becomes attractive when you have a specific reason — smaller upload master, higher compression efficiency, 10-bit/HDR workflow, or a controlled playback environment.

In VSDC, the export decision should come after the editing workflow, not before it. Keep the camera originals, edit with hardware decoding/proxies if needed, then choose the output codec based on the destination. The fact that the source is HEVC does not force the final export to be HEVC, and an H.264 source does not prevent you from producing another supported delivery codec.

Our summary table in H.264 vs H.265/HEVC is meant for exactly this decision: compatibility favors H.264; compression efficiency favors HEVC.