What a batch is

Quick answer

A batch is a named set of files you are replacing in one run, together with the decisions you have made about where each one goes.

Everything WP Bulk Replace does happens inside a batch. You start one, put files in it, tell it which posts and which field to look at, check the matches it proposes, and then run the replacement on the rows you are happy with. Nothing is written to your site until that last step, and even then only for the rows you selected.

The reason the work is organised this way is that replacing a file is not reversible by itself. A batch gives you somewhere to see the whole set before any of it happens, and somewhere to come back to afterwards — the backups, the rollback buttons and the record of what was replaced all belong to the batch, not to a single file.

The four steps

A batch moves through four steps, shown in a bar at the top of the screen:

1. Upload — put the files in. They go into a staging folder, not into your Media Library.
2. Match — choose the post type and the field that holds the file, and let the plugin propose which post each file belongs to.
3. Review & Resolve — check the proposals, fix the ones that are wrong, and skip the ones you do not want.
4. Backup & Replace — run the replacement on the rows you select, then verify and clean up.

Nothing is locked. You can click any step in the bar and go back to it, and re-running matching after you change the field does not undo decisions you have already made by hand.

What a batch does not do

A batch is not a schedule and not a queue. It runs while the browser tab is open, in small chunks, and it stops when you stop it. Closing the tab part-way through leaves the rows that completed as completed and the rest untouched — there is no half-replaced file.

A batch is also not tied to one post type. The post type and the field are chosen per batch, so a batch of course handbooks and a batch of product data sheets are two batches with different settings, not one batch with a filter.