How do I switch from ShortPixel or Imagify?

3 min read · Last updated August 2026

Go to Media > SlashImage, open the Tools tab, then run Scan followed by Migrate now. SlashImage imports the other plugin's optimization records so its work counts as yours, and the WebP and AVIF files it already created are served by SlashImage. Nothing is re-compressed and no credits are used.

Before you start

  • Leave the other plugin active. The Tools tab only lists optimizers that are still active on this site. If you deactivate ShortPixel or Imagify first, its card never appears and there is nothing to migrate.
  • SlashImage 1.2.0 or later. Your installed version is shown on the Plugins page.
  • No API key needed. Migration makes no API calls.

Steps

  1. Go to Media > SlashImage and open the Tools tab.
  2. On the ShortPixel or Imagify card, click Scan. The scan walks your library and writes nothing.
  3. Read the report. It shows how many images are Ready to migrate, how many were already migrated, and what was skipped and why.
  4. Click Migrate now. A scan is required first, so the button is only available once a scan has finished.
  5. When the whole library has been walked, the card offers Deactivate. Use it, so two optimizers are not rewriting your pages at the same time.

What gets imported

The other plugin's per-image optimization records become SlashImage metadata, so your stats, the Media Library SlashImage column, and your savings totals include that work. Its WebP and AVIF files stay exactly where they are and are served in place. Nothing is copied, renamed, or linked.

The other plugin is only ever read. Its tables, settings, files, and backups are never changed. The import is safe to re-run: images already migrated, or already optimized by SlashImage, are skipped rather than overwritten.

The Deactivate offer appears only after a scan and migration have reached the end of that source. A partial import never shows it.

What to watch out for

Migrated images have no SlashImage backup. Restore and Re-optimize are unavailable for them, because SlashImage never held their original files. Those originals stay in the other plugin's own backups, so keep them if you may want to roll back.

Multisite is not supported yet. The migration refuses with: Migration is not available on multisite networks yet, because optimization data is stored separately for each site.

Large libraries

Run the import from the shell instead:

bash
wp slashimage migrate shortpixel --dry-run
wp slashimage migrate shortpixel

The command does the same import in one long-lived process, and it works even if the other plugin has already been removed.

See also

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