LEGO collector tools
Interactive utilities built on our catalog and price data — not just articles. Check set completion, compare inventories, and estimate bulk lot value.
Set completion checker
Pick any official set, mark the parts you already have, and see exactly what is missing — with piece counts and links to each part.
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⚖Set parts comparison
Compare two LEGO sets side by side. See shared elements, unique parts, and overlap percentages — useful when choosing which set to part out or buy for MOCs.
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💰Bulk lot valuator
Build a list of identified parts and get an estimated market value based on recent sold prices. Ideal for pricing yard-sale finds and marketplace lots.
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🧱What can I build?
Add sets you already own and discover other official sets where you have most of the parts — overlap percentages from merged inventories.
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Bulk lot sorting workflow
New to yard-sale lots? Follow our step-by-step guide: scan parts, estimate value, check set completion, and export missing pieces as a CSV.
Start the workflow →Browse by color
Our color reference lists every official LEGO color with RGB swatches, part counts, and year ranges. Essential when sorting bulk lots or identifying gray/bluish-gray era parts.
Browse LEGO colors →How these tools help
For rebuilders
The set completion checker turns a parts inventory into a checklist. Mark what you have, export what's missing, and stop guessing whether a lot is complete.
For MOC builders
Set comparison shows overlap between two official sets — helpful when deciding which retired set to buy for specific elements.
For sellers
The lot valuator sums recent sold prices for identified parts so you can price bulk lots with data instead of gut feel.
Learn the workflows
Our collector guides explain the theory; these tools let you apply it immediately.