Check your photo against Heureka's rules.
Heureka sets rules for the main image that can be measured from the photo: background colour. Drop a photo to see which ones it meets. It runs in your browser; nothing is uploaded.
Choose a marketplace and a photo.
Rules come from each marketplace's own help pages, summarised in the guides (checked 27 September 2026). Size, file size and format are checked as well.
What Heureka asks for.
Source: Heureka — Jak správně posílat obrázky · checked 27 September 2026
- Main image
- White background (recommended)
- Size
- At least 20 × 50 or 50 × 20 pixels and 30 kB, with at least 175 × 175 pixels recommended; at most 4,096 × 4,096 pixels and 2,000 kB
- Formats
- JPEG and PNG are supported on both official pages; the XML feed specification also lists WebP and BMP, while the image help page says only .jpeg, .png and .jpg are currently supported
- Background
- Ideally white; the XML feed specification adds that an image should not have a transparent background
- Clothing and shoes
- Heureka.cz's fashion conditions require a quality image in the matching colour for every colour variant and recommend 160,000 pixels (about 400 × 400) or more; clothing should not be shown folded or hung but ideally on a figure, and a shoe image should show only the shoes
- Not allowed
- A watermark, a discount or bonus, a specific seller's logo, or any highlight of the product's strengths, awards included; such images are blocked
- Heureka Marketplace
- A shop in Heureka Marketplace that sends watermarked images does not appear in the TOP position on the product card, even with the best offer; it is shown only in the price comparison
- Feed
- The main image goes in IMGURL and further views, such as another angle or the whole package, in IMGURL_ALTERNATIVE; a new image needs a new URL
How each rule is measured.
- Background colour
- The background colour is the median of a thin band along all four edges. A pure-white rule passes only when that band is RGB 255, 255, 255; near-white values such as 253 are reported with their exact colour.
- Scene photos
- Room and lifestyle photos have no plain background to measure against, so fill, edges and shadow are marked as not measured rather than guessed.
Checkers by marketplace.
Heureka main images, answered.
What background does Heureka require for the main image?
White background (recommended). The checker reads the background from the edges of the photo and reports its exact RGB value.
What size should Heureka product images be?
Heureka feed images: at least 20 × 50 px and 30 kB, 175 × 175 px recommended, at most 4,096 × 4,096 px and 2,000 kB; ideally white, not transparent.
Where do these figures come from?
From Heureka — Jak správně posílat obrázky, read on 27 September 2026. Marketplaces update their rules; the official page is the final reference.
Is my image uploaded?
No. The file is read and processed inside your browser; nothing is sent to a server.
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