---
title: "How Herofab checks marketplace image rules | Herofab"
description: "Where the marketplace rules on Herofab come from: official pages only, nothing added, each dated, and every figure counted from the same data."
url: https://herofab.app/guides/how-we-check-marketplace-rules
language: en
updated: 2026-09-30
---

# How we check marketplace rules.

Every image rule on this site comes from the marketplace's own pages, states only what they say and carries the date it was read. This page explains the method.

![The folded indigo jeans with turned-up hems on a white background](https://herofab.app/img/ex/jeans-white-1100.webp)

Made with Herofab · Remove background

## Official pages only

Each marketplace guide is built from the marketplace's own pages: its help centre, seller centre, partner guidelines or official documents. The guide links to them and shows the day they were read. A rule that appears only on a third-party site is left out.

## Nothing added

Each rule states only what the marketplace's page says, with nothing added. Where a page recommends rather than requires, the guide says recommended.

## Figures counted, not typed

The figures on the statistics page, such as how many marketplaces ask for a pure white background, are counted from the same guide data each time the site is built. No figure is typed by hand.

## One set of rules

The free product photo and image size checkers read the same rules as the guides and measure a photo in your browser; the photo is not uploaded. Tool comparisons use each company's own website, with the date it was read; a dash means the feature is not listed there.

## Dates and corrections

The date on a guide changes only when its sources are read again. To report a rule that has changed, write to support@herofab.app with the marketplace and the page.

## Checklist

- An official source is linked on every guide.
- Every guide shows the day its sources were read.
- Recommendations are marked as recommended.
- No figure is typed by hand.

> **With Herofab**
>
> The guides, the statistics page and the product photo checker share one set of rules, so the checker and the guide do not disagree.

Updated 30 September 2026

## In short.

**Where do the rules come from?**

From each marketplace's own help centre, seller centre, partner guidelines or official documents. Every guide links to its sources.

**What happens when a rule changes?**

Write to support@herofab.app with the marketplace and the page. The guide is corrected, and its date updated, after the official page is read again.

Related

[Marketplace image rules](https://herofab.app/guides/marketplace-image-rules) · [Marketplace image rules in numbers](https://herofab.app/guides/marketplace-image-statistics) · [Product photo checker](https://herofab.app/tools/product-photo-checker) · [All guides](https://herofab.app/guides/)