CardComps — Card Values for eBay icon

CardComps — Card Values for eBay

by james.lagnese · Shopping
Manifest V3 Free
View in Chrome Web Store Data as of 15 Oct 2026

Instant eBay sold-comp fair value + margin on eBay sports-card listings.

Users
33
+2 in 30 days
Rating
5.0 / 5
unchanged in 30 days
Ratings
3
+2 in 30 days
Store rank
#125K
#104K among extensions
Version
1.3.0
updated 11 Aug 2026

Users

monthly, 3 months
01836Jul 2026Sep 2026Oct 2026
Latest, 15 Oct 2026: 33 usersMove the mouse over the chart for any month

Ratings count

monthly, 3 months
023Jul 2026Sep 2026Oct 2026
Latest, 15 Oct 2026: 3 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About CardComps — Card Values for eBay

CardComps puts a fair-value estimate on every eBay sports-card listing, so you can tell a deal from a trap without leaving the search page. Each result gets a rating chip as you scroll — Excellent, Great, Good, Fair or Bad — based on how far under fair value the asking price sits. Click the Value button on any listing for the full picture: what that exact card has actually been selling for, the range it trades in, how recently, and your margin. REQUIRES AN EBAY SIGN-IN eBay shows completed and sold listings only to signed-in users, so CardComps needs you signed in to eBay in the same browser. It never sees or stores your credentials — requests ride your existing session, exactly like any other page you load. If you are signed out, the extension tells you so rather than pretending the card has no sales history. WHAT YOU GET • Fair value from real sold comps, not wishful asking prices • A deal rating on every search result, filled in as you scroll • The individual sales behind every number, with thumbnails, linked to the real sold listings • Gross and after-fee margin against the current bid • Price-over-time chart with a trend line • Grade and Variant menus — including free-text entry — to price the exact card in front of you • Works on search results and on individual listing pages BUILT TO BE HONEST Matching cards is the hard part, and a confident wrong number is worse than no number at all. Before counting a sale as a comp, CardComps checks the release year, print-run serial, autograph status, product line, grade and parallel. When comps disagree too much, or there simply are not enough of them, it says so instead of guessing. Best Offer sales are counted at 85% of asking — eBay hides the real accepted price — and flagged wherever they appear. Sold data covers roughly the last 90 days, which is as far back as eBay's public search goes. PRIVATE BY DESIGN Everything runs inside your browser. There is no server, no account, no tracking, and no data collection of any kind. The extension caches the sale records it reads from eBay on your own device for a day so it does not re-request the same searches; nothing is ever sent anywhere.

Growth

WindowUsersChangeRatingsRating
7 days+4+13.8%00.00
30 days+2+6.5%+20.00

Chrome Web Store search rankings

Where CardComps — Card Values for eBay appears when people search the store, with the 30 day change
Search phrasePosition30 days
value#88+8

Version history

3 versions recorded
1.3.011 Aug 2026
1.1.029 Jul 2026
1.0.026 Jul 2026

Details

Category
Shopping
First seen
26 Jul 2026
Size
76 KB
Languages
en-US
Pricing
Free
Privacy policy
gist.github.com
Extension ID
hgajmdjmbiaojkpgjhbhcgnccolhcicj

Permissions and risk

Moderate riskimpact 1, likelihood 3
Permissions
storage

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