Chrome extension · Facebook Marketplace

Is it the right car?Find out in one click.

Curbside checks any Facebook Marketplace car listing and tells you whether the price is fair, whether it looks like a scam, how much room you have to negotiate, and what to ask the seller.

Add to Chrome — free

Runs only when you click it.
Marketplace vehicle pages only.

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.

Curbside panel for a 2019 Toyota Corolla SE Hatchback scoring 88 out of 100, with a clean title.

88 Buy this one.

Clean title, asking below the comparable range, and nothing dragging it down. Sixteen days listed, so there's still moderate room to negotiate.

Curbside panel for a 2019 Toyota Corolla SE Sedan scoring 75 out of 100, flagged with a rebuilt title.

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.

Curbside panel for a 2017 Toyota Corolla SE scoring 63 out of 100, with a rebuilt title and better-priced alternatives nearby.

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.

The score

Other deal scores hide their math. This one shows it.

Four readings, each weighted, each visible. You can see exactly which one pulled the number down and by how much — and if you disagree with a weight, you can see that too. A number you can't check is a number you shouldn't trust.

  • 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 is scored separately, never folded in. A rebuilt-title car priced low for exactly that reason is a risky car that's fairly priced. One number can't say both things at once.
  • 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.
2017 Corolla SE — asking $10,500
price residual73 × 50% = 36.5
vehicle risk25 × 25% =  6.3
seller / scam75 × 15% = 11.3
information87 × 10% =  8.7
total62.8 → 63
Why the comps matter

Marketplace gives you a price and nothing to judge it against.

Most price checkers compare a private-party car to dealer listings — cars carrying reconditioning markup, warranty, and lot overhead. Against that baseline nearly every Marketplace car looks like a steal. Curbside compares it to the only fair benchmark: other private sellers, right now, near you.

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.

What it checks

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

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.

Scam

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.

Vehicle

What's wrong with this car?

Open safety recalls, complaint density for this model year, and title flags — salvage, rebuilt, branded — from free federal NHTSA data.

Leverage

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.

Inspection

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.

Alternatives

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 it works

Three steps, then it's out of your way.

Add it to Chrome

One install. Curbside can only reach Marketplace vehicle pages — nothing else you browse.

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.

What we won't pretend

Two limits, stated up front instead of buried in a terms page.

It's a beta signal, not a rating.

The weights and the discount curve are starting hypotheses. They haven't been checked against a set of hand-evaluated listings yet, and until they are, treat the number as a reason to look closer — not a verdict.

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.

Privacy

It runs when you click it. That's the whole rule.

No background scanning, no monitoring searches while you're away, no watching where else you go.

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.

Sellers stay anonymous

No names, no profile links, no photos, no join dates. A scrambled ID and a count of active listings — that's all that leaves your browser.

Marketplace only

Permissions are scoped to Marketplace vehicle pages. Every other tab you have open is none of its business.

Don't drive an hour to find out.

Check the listing in one click, then decide whether it's worth the trip.

Add Curbside to Chrome — free

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.