Is it the right car?Find out in one click.
Check a Facebook Marketplace car against comparable private-party listings, spot warning signs, and prepare better questions and an opening offer.
Illustrative example, not a live listing.
2017 Corolla SE · asking $10,500BETA
63/100
Fair, not great. Worth a closer look, not a rush.
- Price73
- Vehicle25
- Seller75
- Info87
Higher is better on every reading.
Lowest reading: Vehicle at 25/100 — the biggest drag on this score.
Ask: What's behind the Vehicle reading, before anything else.
50% price · 25% risk · 15% seller · 10% info → 62.8 → 63
Marketplace gives you a price and nothing to judge it against.
A lot of price tools compare a private-party car to dealer listings — cars carrying reconditioning markup, warranty, and lot overhead. Against that baseline almost anything on Marketplace looks like a deal. Curbside compares it to other private sellers, right now, near you, instead.
Dealer benchmark
“$4,100 below market.”
Measured against cars that were detailed, warrantied, and sold off a lot. That gap is the dealer’s overhead, not your discount.
Curbside benchmark
“Below what private sellers ask.”
Measured against comparable listings from people just like the one you’re about to message. Adjusted for mileage and trim.
Three steps, then it’s out of your way.
Add it to Chrome
One install, on desktop Chrome. Curbside only acts on a Marketplace vehicle listing you open and click Evaluate on.
Open a car you're considering
Browse Marketplace the way you already do. Curbside sits quiet until you want it.
Click Evaluate
It reads the listing, pulls comparable private-party listings nearby, and returns the full read in seconds — right over the page.
Six readings on every listing.
Kept separate on purpose. A risky car can be fairly priced, and a clean car can be a bad buy.
Price, Seller & Scam, and Vehicle roll straight into your score, alongside Information (see the breakdown below). Leverage and Alternatives are free reads built from the same comparable-listings search; Inspection draws on known issues for the model instead — none of the three carry extra weight.
Is the ask fair?
An expected range built from comparable listings nearby, adjusted for mileage and trim — and how far this one sits outside it.
Does it smell wrong?
Flags the patterns real scam listings share: far below market with no reason given, thin or templated descriptions, wire-only payment, won't meet in person.
What's wrong with this car?
Recall campaigns issued for this model, owner complaint counts, and title flags — salvage, rebuilt, branded — from what the listing states, cross-checked against free federal NHTSA recall and complaint data.
How much room do you have?
Days on the market, price drops, and seller wording that signals motivation — then an offer in three moves, and a message you can edit and send.
What should you ask?
The known failure modes for this model at this mileage, so you show up asking about the transmission instead of nodding at the paint.
Is there a better one?
Similar cars listed nearby at better prices — because sometimes the honest answer is that the next listing down is the one you want.
How the score is weighted
- Price residual carries half the score — how far the ask sits from what comparable private-party listings suggest, adjusted for mileage and trim.
- Vehicle risk gets its own line, and its own weight in the total. It’s never hidden inside the number — a rebuilt-title car priced low for exactly that reason still shows up two ways: a fair price, and a risk warning that isn’t averaged away.
- Seller and scam risk stands on its own, so a warning arrives as a warning — not as a few points quietly shaved off a total you’d never notice.
- Information completeness rewards sellers who actually told you something, and marks down the listings that left you guessing.
Illustrative examples · beta scoring
Three Corollas. Three very different answers.
Same car, same city, prices within $400 of each other — and the reason they score differently is on the screen, not hidden inside a number.
88 Worth a closer look.
Clean title, asking below the comparable range, and nothing dragging it down. Sixteen days listed, so there's still moderate room to negotiate.
75 Cheap for a reason.
The title is rebuilt, which drops vehicle risk to 25/100 — but the price is low enough to carry it. Listed 76 days, so the leverage is strong if you still want it.
63 Keep looking.
Same rebuilt title, two years older, and asking more. Four comparable listings in the same search are better priced for what they are.
What to know before you trust the number.
No background scanning, no monitoring searches while you’re away, no watching where else you go.
These are asking prices, not sale prices.
Marketplace never shows what a car actually sold for. Every figure here describes how comparable vehicles are advertised. That’s a weaker claim than a valuation, and you should know it going in.
You start every check
Curbside reads a listing only after you click Evaluate on a page you already opened. It never crawls Marketplace on its own.
Seller data, minimized
No names, no profile links, no photos, no join dates. A scrambled ID, a count of active listings, and the star rating Marketplace already shows on the listing — that’s what leaves your browser.
Scoped to Marketplace
The extension can read Marketplace pages, but it only acts — and only sends anything — when you click Evaluate on a vehicle listing you’re viewing. Every other tab you have open is none of its business.
Your first 10 checks are free. Then pay for what you use.
Buying a car is a few weeks of your life, not a subscription you forget about. Buy a pack of checks, or go unlimited for the month you’re actually shopping and stop when you’re done.
10 checks
On install, no card. Enough to judge whether this is worth paying for.
$7.99
One car-shopping weekend.
$11.99
Better per-check price.
$16.99/mo
For the month you're actually shopping.
Don’t drive an hour to find out.
Check the listing in one click, then decide whether it’s worth the trip.
Beta signal, not a rating: the weights are starting hypotheses that have not been checked against hand-evaluated listings yet. Curbside is an informational tool for evaluating listings. It is not a purchase recommendation, an appraisal, or a substitute for a pre-purchase inspection and a vehicle history report. Curbside is not affiliated with, endorsed by, or connected to Meta Platforms, Inc.