Check image bit depth and colour mode

Walmart's Image guidelines table has a Color Format row reading RGB and, further down the same table, a Bit Depth row reading 8 bits per pixel. Walmart does not present these two cells as being in tension; reading 8 bits per pixel as 8 bits per channel is this tool's interpretation, which is why a 16-bit PNG is flagged on this row. An indexed (palette) PNG whose IHDR records 8 bits per palette index reads as 8 on this row; a 1-, 2- or 4-bit palette PNG reads as that lower figure. Either way an indexed file is reported as not RGB on the colour mode row, because the IHDR value is bits per palette index rather than bits per channel. Two kinds of PNG read differently from an ordinary export: a 16-bit PNG, which some editors write by default, and an indexed or palette PNG, which stores a palette index per pixel rather than RGB values — for a palette PNG the header records bits per palette index rather than bits per channel, and this page prints that header value under the same “bits per channel” label it uses for every file, so read it as the palette index depth. This tool reports both cases. The convert option's JPEG copy is written at 8 bits per channel in RGB; its PNG copy is quantised to a palette of at most 256 colours and comes back as an indexed file, so JPEG is the output to pick for an 8-bit RGB copy. The 1, 2, 4, 8 and 16 bit depths and the 256-colour palette ceiling come from the PNG format and this tool's own encoder, not from Walmart's page, which states only Bit Depth: 8 bits per pixel.

Our verification record of Amazon's Product image guide (G1881) paraphrases colour mode as RGB preferred, with CMYK files to be converted to RGB before uploading; we hold no verbatim capture of that line, and the sentence we did capture from the page is: Do not rely on ICC color profiles for accurate color display on Amazon. A JPEG saved from a print workflow is often CMYK or YCCK — four components with an Adobe APP14 marker — which this tool reports. The convert option's JPEG copy is written in RGB from the pixels your browser decodes; its PNG copy is quantised to a palette of at most 256 colours and comes back indexed rather than RGB. How Amazon treats any particular upload is decided by Amazon's own checks.

It depends on the platform, and this tool only reports. Our record of Amazon's page paraphrases it as greyscale being acceptable only where the product itself is grey or silver metallic, which describes a silver product; we hold no verbatim capture of that line, so treat it as our reading of the page rather than its wording. TikTok Shop's official Seller University listing rules state: Images must be in color. Black-and-white images are not acceptable. Our record captures that line from the two Seller University pages listed under sources without attributing it to one of them, and records no exception to it, but it captures selected sentences rather than the full pages, so read the linked pages for yourself. TikTok Shop’s line appears in the spec table above under the page it came from; the Amazon grey-or-silver-metallic reading is a paraphrase from our verification record, not wording we captured, so it is not given a row. Walmart's table addresses colour format (RGB), not whether the picture has colour, and the Etsy and Allegro pages we verified do not address it. The reading is the mean colour saturation of the decoded pixels, measured on a sample of those pixels for large images, including a white background, so a small colourful product on a large white canvas can also read as low saturation; look at the mean saturation figure as well as the label.

Colour mode is how the file stores pixels: a greyscale-mode file has one channel per pixel, an RGB file has three, a CMYK JPEG has four. Greyscale content is what the picture shows: an RGB file can hold a black-and-white photograph. TikTok Shop's line is about the picture, so this tool measures the decoded pixels as well as reading the header, and reports both readings on the same row. They are separate measurements for a file with more than one channel; a single-channel file is reported as greyscale content by definition, so there the content reading restates the header.

An ICC profile is a block of metadata describing the colour space the pixel values are meant in; PNG stores it in an iCCP chunk and JPEG in an APP2 ICC_PROFILE segment. Amazon says not to rely on ICC colour profiles for accurate colour display on Amazon; the pages we captured carry no instruction to remove an embedded profile, so dropping it is our reading of that line rather than wording we captured from Amazon; our own record reads the same line as implying the profile should be stripped. Etsy suggests converting to sRGB before uploading if colours look different after upload, and Allegro says that to keep full colour fidelity you should not use profiles other than sRGB. This tool reports whether a profile is present and does not read its contents. The converted copy carries no profile and is re-encoded from the pixels your browser decoded into its sRGB canvas — the JPEG option as a lossy save, the PNG option quantised to a palette of at most 256 colours — so neither copy is pixel-identical to the original.

It can. The extra precision a 16-bit file carries is discarded: the copy is taken from the pixels your browser decoded into its sRGB canvas at 8 bits per channel, so a gradient that relied on that precision can band. What happens beyond that depends on the output format you pick. The JPEG copy is a lossy save, so it is not pixel-identical to the original even where the 8-bit values would have matched. The PNG copy is quantised to a palette of at most 256 colours, a heavier change to the pixels, and it is written as an indexed (palette) PNG, which this page's own colour mode reading reports as not RGB. Keep your original for editing. The file you uploaded is never modified; the copy is a separate download.

Etsy's help article says: Animated .gif files & transparent .png files are not supported. If a file contains transparency, the transparent parts of the image will appear black on Etsy. This tool reports an alpha channel as RGB with alpha or greyscale with alpha. The convert option composites transparent areas onto white before writing the copy; the etsy-transparent-png-black-fix tool does the same alongside Etsy's other lines.

JPEG and PNG. The header readings come from the JPEG SOF and APP segments and the PNG IHDR, PLTE and iCCP chunks, which this tool parses directly. TIFF, GIF, BMP, WebP, HEIC and SVG are not read here even where a platform accepts them — Amazon lists TIFF and non-animated GIF, Walmart lists BMP, Etsy lists .gif, .svg and .heic, and Allegro accepts WEBP through the API or file listing. Animated PNG files are declined.

The official pages we verified for eBay and Shopify address formats, pixel and file-size limits, aspect ratios, and — for eBay — what may appear in the picture (no watermarks, borders or added text). Shopify's two pages disagree on their pixel limits: the product media page gives 5000 × 5000 px or 25 MP with a file size under 20 MB, while the theme images page gives 20 MP or 20 MB. Neither Shopify page states a background rule or a share-of-frame rule. For Shopee (Seller Education Hub, Singapore market, articles dated 2024-04-15 and 2023-01-11 plus an undated Mall PDF) the official sources state no pixel limits and no file-size limit. None of these records contains a line on bit depth, colour mode or colour profiles, so this page attaches no wording from those platforms. The readings are still shown for any JPEG or PNG you upload.

No. The pass/fail line covers the RGB colour mode row, and the bit-depth row is flagged rather than failed: Walmart's cell reads “Bit Depth: 8 bits per pixel”, and reading that as 8 bits per channel — the reading that fails a 16-bit PNG — is this tool's interpretation, not Walmart's wording. Both readings are set against the official wording linked in each row. Walmart's colour cell reads Color Format: RGB and says nothing about an alpha channel; treating RGB with alpha as RGB is this tool's decision, not Walmart's wording, so an RGBA file is reported as RGB with alpha and is not failed on that row. Every platform runs its own checks on upload, and the same pages carry other lines on size, background and content that this tool does not read. The linked official page is authoritative; this page shows you the readings and the date we last verified the wording.