Suno Extend, Replace Section and Stem Split: How to Use

Updated 2026-09-10 · Suno-API team

Learn how Suno extend, replace section and stem separation work, what each costs at 0.6 yuan per call, and which one fits your edit.

Once you have a song you are happy with, you usually still want to adjust part of it. The platform offers three common editing features, each priced at 0.6 yuan per call, and you can combine them as needed.

Extend: make the song longer

Extend continues generating from an existing song. It suits tracks that are too short, or cases where you want to add another chorus. You need to specify the time point where the extension starts and give an extension description, for example "continue the chorus mood, add stronger drums".

Note that the extension start point must be earlier than the total song duration, otherwise you get an invalid parameter error.

Replace section: change only the middle part

Replace section is for local edits, such as rewriting the second verse or redoing the arrangement in one middle passage. You provide the start and end time of the replacement and the new lyrics. Compared with regenerating the whole song, this costs less and keeps the parts you already like.

Stem separation: split vocals and instrumental

Stem separation breaks a song into separate audio tracks. The two most common modes are two stems (vocals + instrumental) and twelve stems.

The stem result is multiple audio objects, so you need to handle each one according to the structure returned by the API.

Requirements

• The source song must belong to the current account and must have finished generating.
• Songs that are still generating or that failed cannot be used as a source.
• Do not use the temporary placeholder IDs shown on the page.

You can run these features directly in the online studio; for batch use, go through the API.