Discover Chemical Compounds by Element
Don't know the exact formula? No problem. Select elements from the periodic table and explore all known compounds containing those elements.
Select Elements
Click up to 5 elements, then view compounds
Why CompoundLookup?
The problem we solve that no other tool does
- ✗Require exact molecular formula (H₂O, NaCl, C₆H₁₂O₆)
- ✗Must know compound name or CAS number
- ✗No way to explore "what compounds have Carbon and Nitrogen?"
- ✓Just select elements - no formula needed
- ✓Discover compounds you didn't know existed
- ✓Perfect for students, researchers, and curious minds
How It Works
Three simple steps to find compounds
Select Elements
Click on any elements in the periodic table. Select up to 5 elements for your search.
Search Database
We search our database of 7.5+ million compounds indexed by element combination.
Explore Results
Browse compounds with formulas, IUPAC names, and links to PubChem for full details.
Popular Combinations
Frequently searched element combinations
Frequently Asked Questions
Everything you need to know about CompoundLookup
What makes CompoundLookup different from other chemistry databases?
Unlike PubChem, ChemSpider, or other databases that require you to know the exact molecular formula, CompoundLookup lets you search by simply selecting elements. Just pick the elements you're interested in, and we'll show you all known compounds containing those elements.
Where does the compound data come from?
All compound data is sourced from PubChem, the world's largest free chemistry database maintained by the National Institutes of Health (NIH). We organize and index this data by element combination to make it searchable in a way that wasn't possible before.
How many compounds are in the database?
Our database contains over 7.5 million compounds organized into 200,000+ unique element combinations. We continuously update our data from PubChem to ensure accuracy.
Can I search for compounds with more than 5 elements?
Currently, you can select up to 5 elements at a time. This covers the vast majority of common compounds. We're working on expanding this limit in future updates.
Is CompoundLookup free to use?
Yes, CompoundLookup is completely free. Our mission is to make chemistry data more accessible to students, researchers, and curious minds everywhere.
Ready to Explore?
Start discovering compounds by selecting elements from the periodic table above.
Start Searching