Transparency
How Item Value Checker turns a photo into a price
No black boxes, no proprietary “AI magic” marketing. Here's exactly what happens between the moment you upload a photo and the moment you see a value estimate — including the limits of what we can do.
Clear, well-lit, full item in frame works best.
The 4-step process
You upload a photo
Drop, click, or paste any image. The clearer the photo (good lighting, full item visible, brand markings legible), the better the match. We resize images client-side to 1200px max for faster upload and to keep the API request small.
eBay's image search finds visual matches
We send the image bytes to eBay's Browse API search_by_image endpoint. eBay's vision model returns the most visually similar active listings — typically 20-27 results ranked by visual confidence. We don't run our own image recognition; we use eBay's because their dataset is the largest and freshest in resale.
We analyze the comps statistically
From the matched listings, we calculate the MEDIAN price (more robust to outliers than mean), the price range (min and max), and a confidence score based on the standard deviation. A 0.85 discount factor is applied because resale typically clears below the asking price most sellers are advertising.
You see the estimate + matched listings
You get the median price, the full range, a confidence percentage (how tightly clustered the comps are — high = predictable, low = high variance), and links to every comp we used so you can verify each one yourself. We don't hide our work.
Honest about the limits
We can't see condition from one photo. A beat-up iPhone with a cracked screen and an immaculate one in the original box look similar from the front but sell for very different prices. The estimate assumes “average used condition” — adjust up or down based on what you actually have.
Visual similarity isn't perfect identity. Sometimes we match the right brand but the wrong model. Always glance at the matched listings shown in the results to verify — if the comps look very different from your item, the estimate is probably wrong.
Rare items have huge price spreads. A regular Pokemon card vs a 1st edition holographic one — same image search, very different sold prices. Low confidence + wide range is the signal that you should research more carefully.
Niche or obscure items return weak data. If your item has only 1-3 eBay matches, the estimate is essentially “here's what someone listed it for once” — not a reliable market signal.
Why eBay sold listings as the source
eBay processes more secondhand resale transactions than any other public US marketplace. Sold listings (vs active listings) are the only data that shows what buyers actually paid, not what sellers hope to get. Asking prices on Facebook Marketplace, Craigslist, and Mercari are aspirational; eBay sold prices are real.
We also pull from eBay's active listings as a directional check, but the median and range are anchored to recent sold data. If you want to dig deeper into raw sold listings yourself, see our guide: How to find real eBay sold prices.
How to use the result
If you're selling: Use the median as your “Buy It Now” starting price. If your item is in better-than-average condition, list 10-25% above. If worse, 10-25% below. Watch the matched listings — if the same item is selling fast at that price, you're priced right. If your listing sits without offers for 2 weeks, drop the price.
If you're buying: Use the range as a sanity check. Anything below the min is a great deal (assuming condition is good). Anything above the max is probably overpriced. Negotiate toward the median.
If you're flipping: Apply the “3x rule” — only buy if you can resell at 3x your acquisition cost (covers fees, shipping, and time). See our thrift-flipping pricing guide for a full framework.
Speed it up with the browser extension
For people who check 10+ items per session — thrift flippers, FB Marketplace scrollers, dealers — the website workflow has friction. Right-click → done is faster than save-image, switch-tab, upload, wait.
Get the free Chrome extensionWhat's new in 2026
We ship visibly. Below is the recent shipping log so you can see how active development really is — not a marketing claim, just commits.
May 2026
Per-marketplace fee calculator landings
eBay, Mercari, and Poshmark fee calculator pages with platform-specific FAQ and deep-dive content. Pre-fill from any value-check result.
May 2026
Reseller ROI Calculator
Net profit, ROI %, and margin % across 7 marketplaces with real fee structures. Cross-promoted from every value-check result page.
May 2026
AI Listing Generator
Photo → eBay/Mercari/Poshmark title and description. Live on /listing-generator, inline on every result page, and built into the Chrome extension popup. Powered by Claude vision.
May 2026
Chrome extension v0.7 + v0.8
CSV export for Recent and Saved lists, plus inline AI listing copy generator with persistent marketplace selection.
May 2026
Bulk value checker
Drop up to 5 photos at once, get a CSV of estimates. Pro tier expands the limit.
April 2026
WorthPoint, PriceCharting, ScoutIQ comparison pages
Honest comparisons against the paid alternatives, including when each tool actually wins.
April 2026
Chrome extension marketplace overlays
Inline value badges on Facebook Marketplace, Craigslist, OfferUp, and Mercari listings with deal-quality color coding.
April 2026
/tools, /pro, /bulk, /contact, /how-it-works
New top-level pages building out the resource library. Saved + Recent tabs in the extension popup.
For the unabridged log, see the public commit history on GitHub.
Live now · 7-day free trial
Item Value Checker Pro
Bulk uploads (drop 20+ photos at once), unlimited extension lookups, price-drop alerts, and AI listing copy. 7-day free trial, then $7/mo for first 500 signups.
Try Pro free for 7 days