Amazon Listing Checker
Four pre-flight checks before your listing goes live: main image compliance, search-terms bytes, title hygiene, A+ sizes. All local, all free, no sign-up.
Main image compliance checker
Resolution, square ratio, white background and file size — checked locally, the image never uploads.
Backend search terms — byte counter
The generic-keywords field counts UTF-8 bytes, not characters — accented words burn the budget twice. Limit: 250 bytes.
Title analyzer
Length vs the 200-character guideline, ALL-CAPS shouting, and duplicate words.
A+ content size finder
Drop an image and see which standard A+ module slots it can fill without cropping.
Why sellers pre-flight here
Local by design
Your product images and listing copy are business assets. Every check runs in your browser — nothing uploads, nothing is stored.
Byte-level truth
The generic keywords field counts UTF-8 bytes, not characters. One accented word can double-charge your budget; the counter shows the real cost.
Four checks, one page
Image, search terms, title and A+ sizes in a single pass — the pre-flight ritual before every listing goes live, in one tab.
Rules, cited honestly
Thresholds reflect widely-published Seller Central requirements and change without notice — each check tells you what it verified so you can re-confirm.
Frequently asked questions
What are Amazon main image requirements?
The main image must have a pure white background (RGB 255,255,255), be a square that fills 85%+ of the frame, represent only the product (no props, logos or text), and be at least 1000px on the longest side for zoom — 1600px or more is the practical standard. The checker verifies resolution, ratio, corner-sampled whiteness and file size locally.
How many bytes is the Amazon backend search terms field?
The generic keywords field allows fewer than 250 bytes. Bytes, not characters: an accented letter like é costs 2 bytes. Repeated words add nothing — Amazon indexes a term once — so the counter flags duplicates you can delete for free space.
How long can an Amazon title be?
Many categories cap titles around 200 characters, and mobile shows far fewer. Beyond length, all-caps words and repetition read as spam to shoppers and can draw suppression risk. The analyzer scores all three.
What sizes do A+ content images need?
Standard A+ modules use fixed slots — for example the image header at 970×600, single side images at 300×400, and comparison chart images at 150×300. Drop an image on the A+ finder to see which slots it can fill without cropping. Always confirm current specs in Seller Central, they occasionally change.
Are my images uploaded anywhere?
No. Image analysis runs on your device with canvas — the files never leave your computer, and you can use the tools offline once loaded.