Media Spec Auditor
Select a batch of product images or videos. You get a matrix — every file against every marketplace — because the question is not "is this image OK" but which of these forty is going to fail, and where.
🔒 Your data never leaves your browser — files are read locally and never uploaded.
A matrix, because that is the shape of the decision
A per-file report tells you each image is fine or not. What you actually need to know before a bulk upload is which channel is going to reject how much of this batch — and whether it is worth re-exporting everything or just the six that fail on one platform.
The same file passes one marketplace and fails another
A 12.5 MB photo is fine for Google Shopping and over eBay's limit. A WebP export is accepted by Google and eBay and not by Amazon. These are exactly the differences that turn one export process into three, and they are invisible until an upload fails.
Transparency is detected by decoding, not guessed from the extension
A PNG may or may not have transparent pixels. This page decodes a sample of the image and looks at the alpha channel, so a flattened PNG is not flagged and a genuinely transparent one is. Transparency matters because platforms composite it against their own background, which is not always white — the halo appears for buyers and never in your editor.
What the browser cannot tell you about a video
Duration and frame size, yes. Codec, no. A browser exposes no reliable way to read whether a file is H.264, HEVC or VP9, and most platform video specs require a particular one. So every video result here says so explicitly — a pass covers dimensions, duration and container only, and the codec still needs checking in your editor.
Where the numbers come from
Google's and eBay's published requirements, both linked in the rules below. Amazon's image requirements live in Seller Central behind a login and vary by category, so those values are labelled as the general marketplace ones rather than presented as your category's rule. Currently carrying 3 platform profiles.
Every check this tool runs (11 rules)
MED-S01 Below a platform’s minimum pixel size
Every marketplace sets a floor on the shorter side. Below it the image is rejected at upload or the product is disapproved — it is not scaled up for you.
Fix: Re-export from the original at a larger size; upscaling an already-small file does not help.
Source: Google Merchant Center Help — Image link [image_link]
MED-S02 Above the minimum but below the recommended size
The image will be accepted, but zoom and hover-magnify need more pixels than the floor provides. Listings that cannot zoom convert worse, and the difference is invisible until a buyer tries.
Source: Google Merchant Center Help — Image link [image_link]
MED-S03 Exceeds a platform’s maximum dimension
Very large images are rejected rather than resized.
Source: Amazon’s image requirements live in Seller Central behind a login and vary by category — search Seller Central Help for "product image requirements". The values used here are the general marketplace ones; treat them as a starting point rather than as your category’s rule.
MED-B01 File is larger than the upload limit
The upload is refused on size regardless of dimensions. Re-encoding a JPEG at a lower quality usually fixes it with no visible difference.
MED-F01 Format not accepted by a platform
Each marketplace publishes the file types it takes. WebP in particular is accepted by some and not by others, which is how one export ends up working on one channel and failing on another.
Source: Google Merchant Center Help — Image link [image_link]
MED-A01 Aspect ratio outside what the platform lays out well
A ratio the platform does not expect gets letterboxed or cropped in the grid, and the crop is centred rather than chosen. On eBay the published guidance is 1:1 or 16:9.
MED-T01 Image has an alpha channel
Transparency is composited against whatever background the platform uses, which is not always white — the result can be an outline or a grey halo the seller never sees in their own editor.
Fix: Flatten onto white before uploading.
Source: Amazon’s image requirements live in Seller Central behind a login and vary by category — search Seller Central Help for "product image requirements". The values used here are the general marketplace ones; treat them as a starting point rather than as your category’s rule.
MED-V01 Video is longer than the platform allows
Over-length video is rejected at upload rather than trimmed.
Source: Own engineering rule: duration limits vary by platform and programme, so the limit is an input here rather than a built-in constant.
MED-V02 The video codec is not checked, and cannot be
A browser reports a video’s duration and frame size but not its codec. Most platform video specs require a particular codec — H.264 is the usual one — so a pass here covers dimensions, duration and container only. Check the codec in your editor before uploading.
Source: Own engineering statement of a browser capability limit.
MED-N01 Metadata only — pixels are not inspected
This audits dimensions, file size and format across platforms. It does not look at the pixels, so it says nothing about the background, the crop, or whether the product fills the frame — the main image checker does that for one image at a time.
Source: Google Merchant Center Help — Image link [image_link]
MED-P01 Passes every selected platform
Dimensions, file size and format are within limits everywhere you selected.
Source: Google Merchant Center Help — Image link [image_link]
Metadata only — dimensions, file size, format, duration. The pixels are not inspected here; the main image checker does that for one image at a time.