Auto parts search,
finally done right.

Who PartLine Is For

PartLine was built for two types of people who fix cars:

DIY owners who do their own maintenance and repairs. You already know how to change your brake pads — you just don't know whether to buy from RockAuto, AutoZone, or Advance Auto. PartLine answers that in one search.

Independent mechanics and small shops who need to source parts quickly and competitively. You're buying parts every day. Checking five suppliers manually for every job isn't sustainable. PartLine makes it a one-step lookup.

Both groups share the same problem: the auto parts market is fragmented across dozens of suppliers, each with their own catalog, pricing, and availability data. There's no neutral third-party tool that searches all of them at once — until now.

How It Works

PartLine searches five major US auto parts suppliers simultaneously and returns results in a single, sortable view. Here's what happens when you run a search:

1. You select your vehicle — by Year, Make, Model; by VIN; or by license plate. PartLine uses your vehicle data to filter results to parts that actually fit.
2. You enter the part you need — "brake pads," "oil filter," "alternator," "water pump," or any of hundreds of common parts. You can also browse by category.
3. PartLine searches every supplier — RockAuto, AutoZone, NAPA Auto Parts, Advance Auto Parts, and O'Reilly Auto Parts are checked against your vehicle and part. Results come back with estimated pricing, shipping costs, and availability.
4. You compare and click through — results are sorted by total cost (price + shipping) by default. Click any result to go directly to that part on the supplier's site, where you complete the purchase.

PartLine never handles your purchase. You always buy directly from the supplier at their current price. We're the search layer — not the store.

Suppliers We Search

PartLine currently searches the five major US retail auto parts suppliers, which together cover the vast majority of the US aftermarket parts market:

Each supplier has different strengths. RockAuto typically has the lowest prices but ships from multiple warehouses, so shipping can add up. AutoZone and O'Reilly are strong for same-day in-store pickup. NAPA carries a wide range of professional-grade and hard-to-find parts. Advance Auto frequently runs promotions for online orders. Seeing all of them in one view lets you make the right call for your situation.

What Makes PartLine Different

Frequently Asked Questions

Is PartLine free?

Yes, completely free to use. PartLine is a search and comparison tool. You pay nothing to use it. You pay the supplier directly when you decide to buy a part.

Does PartLine sell parts?

No. PartLine is a parts finder, not a retailer. Every purchase happens on the supplier's own website (RockAuto, AutoZone, NAPA, etc.) at their current price. We just help you find the best option.

Does PartLine earn commissions from suppliers?

PartLine may earn affiliate commissions from some supplier purchases at no additional cost to you. This doesn't affect which suppliers are shown or how results are ranked — all five major suppliers appear in every search regardless of affiliate relationships.

How current is the pricing data?

Prices shown in PartLine are estimates based on our catalog data and are intended to give you an accurate directional comparison. Actual prices at each supplier may differ slightly due to sales, regional pricing, or catalog updates. We always recommend confirming the final price at checkout before purchasing.

Which vehicles does PartLine cover?

PartLine covers domestic and import cars, trucks, and SUVs sold in the United States from 1990 to present. If your vehicle isn't found by Year/Make/Model, try entering your VIN — we can often identify the vehicle from the VIN even if it isn't in the standard catalog.

How do I contact PartLine?

You can reach us at partline@polsia.app. We read every message.