Underpriced AI
Photo-to-listing pricing tool with a free extension for Whatnot forms
Underpriced AI is a photo-to-listing and pricing tool for resellers. You photograph an item, it shows a price range based on eBay sold listings, and it drafts the title and description. Whatnot is supported only through its free browser extension, which fills the listing form on your computer. The site does not describe an API or sale detection for Whatnot.
Key features
- Photo identification with a price range tied to real eBay sold listings.
- Titles, descriptions and photos generated for each listing.
- Free Chrome and Firefox extension that fills listing forms on Whatnot, Poshmark, Mercari, Depop, Vinted, Facebook Marketplace, OfferUp and Etsy.
- Direct listing to eBay and Bonanza without the extension.
- Works inside ChatGPT and Claude.
- Publishes weekly accuracy grades against real sales.
Who it's for
Resellers who need fast pricing and listing copy for individual items more than a full inventory system.
Pricing
The first scan is free. Scan packs run from $3 for 5 scans to $70 for 250. The Starter subscription is $5/mo for 30 scans, up to $199/mo for 2,500 on the Scale plan. The extension is free. Checked 2026-11-06 on underpricedai.com/pricing.
Sources
3 comments
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The name doesn't tell you how the Whatnot part works, so here it is. There's no Whatnot integration on their side. What you get is a free browser extension that fills in the Whatnot listing form on your computer with the title, description and price it generated. You still click submit. Same for Poshmark, Mercari, Depop and a few others. eBay and Bonanza are the only ones it lists to directly. Pricing is per scan: first scan free, then packs or a monthly plan ($5 gets you 30 scans). For my weekend thrift hauls the pack pricing works better than a subscription. The price range comes from eBay sold listings, so for weird stuff with few sales, take it with salt.
The weekly accuracy grades they publish are a nice touch. Not many tools do that.
Titles are better than what I write at midnight. I tweak maybe one in five.
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