Feed formats explained: XML vs CSV vs API

The format question sounds technical, but it comes down to a practical trade-off: how your catalog data physically travels from your store to the ad platform. XML, CSV, a spreadsheet or an API each move the same data differently, and the right choice depends less on which is "best" and more on how your catalog behaves. This is a plain comparison to help you pick.

If you want the fields that go inside these formats, the product feed guide covers those; this piece is about the container, not the contents.

XML: the structured default

XML is the most common feed format, usually as RSS 2.0 carrying Google's namespace, which looks like <rss xmlns:g="http://base.google.com/ns/1.0" version="2.0">. Meta accepts both RSS and Atom XML.

Its strength is structure. XML handles long descriptions, special characters and repeated fields like additional_image_link cleanly, without the escaping headaches that plague CSV. If your products have rich data, multiple images, or descriptions with commas and line breaks, XML carries it without fuss.

The trade-off is that XML is harder to read and edit by hand. You rarely open it to eyeball a value; you generate it and trust the generator. The one common failure is a malformed document, usually an unescaped ampersand, which stops the whole feed from parsing.

CSV and TSV: simple and inspectable

CSV (comma-separated) and TSV (tab-separated) are flat tables, one row per product. Google accepts tab-delimited .txt and .tsv; Meta accepts CSV and TSV.

Their strength is simplicity. You can open a CSV in any spreadsheet, scan it, and spot a wrong value instantly. For a small catalog or a quick audit, that legibility is genuinely useful.

The trade-off shows up with messy data. Anything containing commas, quotes or line breaks needs careful escaping, and it is easy to break a CSV by pasting a description with a stray comma. TSV avoids the comma problem but shares the general fragility with complex content.

Google Sheets: a live spreadsheet source

Google treats Google Sheets as a first-class data source. It behaves like a CSV that lives online and updates when you edit it, which is convenient for small catalogs and for supplemental feeds that override a few fields.

It is best for low-volume or manually managed catalogs. For large or automated stores, a generated file or an API is more robust, because a hand-edited sheet does not scale and is easy to break.

APIs: for when timing matters

A feed file, however it is formatted, is fetched on a schedule. That is the key limitation: Meta fetches a scheduled feed at most once per hour, and a scheduled fetch is a floor on how fresh your data can be, not a ceiling.

When timing matters, an API is the right tool. Meta's batch update endpoint (items_batch) pushes price and availability changes directly, without waiting for the next fetch, accepting up to 5,000 items per request. On Google, note that the older Content API for Shopping has been deprecated in favor of the Merchant API, so pre-2025 guides point at the wrong endpoint.

Use an API for flash sales, frequent repricing and fast-moving stock. Use a file for catalogs that change slowly. The wrong-price problem that motivates this is covered in why your catalog ads show the wrong price.

How to choose

The decision is simpler than the options suggest:

• Small, slow-changing catalog: CSV or Google Sheets. Easy to manage, easy to inspect.
• Rich or large catalog: XML. It handles complex data and scale without breaking.
• Fast-changing prices or stock: an API on top of your base feed, so time-sensitive changes propagate quickly.
• Serving several platforms: one solid XML or CSV feed as the shared source, since the core specification is largely common.

Most stores end up with a base file feed plus an API for the fields that change fast, which is the pragmatic middle: a reliable full picture, refreshed quickly where it counts.

The format is the start, not the finish

Whatever format carries your catalog, it delivers the same thing: clean data and a plain product image. That gets your products eligible to serve. Turning that eligible catalog into ads that look like your brand is a separate layer, on top of whatever format you chose.

That layer is what FeedForce handles for Meta catalog ads, applying your brand system and per-placement formatting across every SKU regardless of how the underlying feed is formatted. Pick the format that fits your catalog; the creative work happens after.