AR-15 Build Planner

Build your perfect AR-15

The only AR-15 configurator that checks parts compatibility, compares prices across retailers, and lets you share your build in one link.

31+

Part categories

Free

No account needed

1 link

Share any build

Community builds

Featured Builds

How it works

From idea to build list in minutes

Pick your parts

Browse 31 part categories. Select what you need — upper, lower, barrel, BCG, handguard, trigger, and more.

Check compatibility

Our compatibility engine flags potential issues between your parts — caliber mismatches, gas system length, handguard fit, and more.

Save and share

Save your build to your account and get a shareable link. Show off your setup or get feedback from the community.

Why AssembleAR

Everything you need to build right

Compatibility checking

Flags caliber mismatches, gas system issues, handguard fit, and SBR regulations before you buy.

Price comparison

See prices across multiple retailers side by side. Click through to buy directly from the source.

31 part categories

From complete uppers to individual end plates — every part category you need for a full build.

Shareable builds

Every saved build gets a unique URL. Share with friends, forums, or your gunsmith.

Build checklist

Know exactly which core parts you still need before your build is complete.

Partner retailer products

Browse products from partner retailers directly in the builder and click through to buy.

For retailers

Put your products in front of every builder

Join the AssembleAR partner program and embed an interactive AR-15 builder on your website — pre-loaded with your products and prices. One API connection keeps everything in sync.

Faxon Firearms

Your build starts here.

Free to use. No account required to start.

AssembleAR

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