WooCommerce import error: "504 Gateway Timeout" and execution time exceeded

Which cause is yours?

1. Monolithic files: Split into variation-safe batches (target 500 records)

The built-in importer works through the file in a series of short requests from your browser. Each request has to finish within the limits of PHP and of every proxy in front of your site; a slow request (many images, a busy database, a slow host) ends with a 504, or a 524 behind Cloudflare. Smaller files mean fewer rows at risk and an easier retry.

The danger of manual splitting: If you cut a large CSV into files by row count in a spreadsheet, a variable parent can end up at the bottom of one file and part of its variations at the top of the next. If the first file then stops halfway, you are left with a product that has only some of its variations.

Fix: Split the catalog into files targeting 500 records each, with every parent and all of its variations in the same file. A product family larger than 500 records is never cut: it stays whole in one larger file of its own. Import the files in order (the names below are those CatalogDock gives the batches of a file called catalog.csv):

• batches/catalog.part-001.csv — complete product families, parents before their variations;
• batches/catalog.part-002.csv — the next complete families (a family over 500 records gets a file of its own);
• IMPORT-ORDER.txt — the order to import the files in, and what to check after each one.

2. Image downloading: The biggest hidden bottleneck

For an image URL in the Images column, WooCommerce downloads the file from the remote server during the import, and WordPress then creates the resized copies (thumbnails) that your theme and WooCommerce register. Both happen inside the import requests, so a few rows with several large remote images can take longer than the server allows.

Fix options:

• Add the images to the Media Library first: upload them via Media → Add New (or wp media import on the server), then put their file names into the Images column. WooCommerce looks a file name up in the Media Library; a file copied to wp-content/uploads/ by FTP alone is not registered there and is not found.
• Use fast, direct image URLs: see product images not importing for share links and blocked downloads.

3. Increase PHP max_execution_time and memory_limit

If your host lets you change PHP settings (control panel, php.ini or .user.ini), higher limits can help for the duration of a large import. Values are examples; your host may cap them.

; .user.ini or php.ini, only if your host lets you set them (ask before changing a managed host)
max_execution_time = 300
memory_limit = 512M
upload_max_filesize = 64M
post_max_size = 64M

A php_value line in .htaccess only works when PHP runs as an Apache module; on PHP-FPM or CGI hosting it causes an Internal Server Error. If you do not know how PHP runs on your host, use its control panel or ask support. On managed hosts the proxy timeout in front of PHP (for example Nginx fastcgi_read_timeout) may be shorter than max_execution_time, so smaller batches remain the safer step.

4. Very large catalogs and WP-CLI

WP-CLI has no built-in command to import a WooCommerce product CSV: the wc product commands list, create, get, update and delete single products. Do not rely on a command such as wp wc product import; it is not part of WooCommerce. Third-party import plugins may add their own CLI commands: follow their documentation.

For tens of thousands of records through Products → Import, use batches, keep the tab in the foreground until each file finishes, and start with a staging copy of your store.

Still failing?

• Cloudflare error 524: Cloudflare returns it when your server does not answer within Cloudflare's proxy read timeout. The current default and the options per plan are in Cloudflare's documentation of error 524. Smaller batches are the first step; turning off Cloudflare's proxy for the whole site also turns off its protection and is not a routine fix — ask your host or Cloudflare administrator.
• Variations not appearing: If records import but variations are missing, see WooCommerce variations not showing or linking.
• Duplicate SKU errors: See "Invalid or duplicated SKU" causes & fixes.

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