Comparisons

CompoundLookup vs PubChem vs ChemSpider: What's the Difference?

Compare CompoundLookup with traditional chemistry databases and understand when to use each tool.

5 min read|Updated January 28, 2026

Chemistry Database Comparison

There are several chemistry databases available online. Here's how CompoundLookup compares to the major players.

PubChem

What it is: The world's largest free chemistry database, maintained by NIH.

Strengths: - Comprehensive data (100+ million compounds) - Detailed compound properties - Bioassay data - Free and authoritative

Limitations: - Requires exact formula or name - No element-based search - Can be overwhelming for beginners

Best for: Detailed research when you know exactly what compound you're looking for.

ChemSpider

What it is: Royal Society of Chemistry's database with integrated data sources.

Strengths: - Aggregates multiple databases - Good structure search - Property predictions

Limitations: - Requires formula or structure - No element-based search - Some features require registration

Best for: Structure-based searches and property predictions.

CompoundLookup

What it is: The world's first element-based compound search engine.

Strengths: - Search by selecting elements (unique!) - No formula knowledge required - Intuitive periodic table interface - Perfect for exploration and learning

Limitations: - Less detailed property data - Links to PubChem for full details - Database still growing

Best for: Discovering compounds, learning chemistry, initial research when you don't know the formula.

When to Use Each Tool

Use Case Best Tool
Know the exact formula PubChem
Have a structure drawing ChemSpider
Want to explore element combinations CompoundLookup
Need detailed bioassay data PubChem
Learning chemistry CompoundLookup
Quick compound discovery CompoundLookup

The CompoundLookup Advantage

The key differentiator is simple: no other tool lets you search by elements.

Traditional workflow: 1. Wonder what compounds C and N form 2. Search "carbon nitrogen compounds" on Google 3. Find scattered, incomplete information 4. Manually search each formula in PubChem

CompoundLookup workflow: 1. Click C, click N 2. See ALL carbon-nitrogen compounds instantly

We're not replacing PubChem or ChemSpider—we're filling a gap they can't fill. Use CompoundLookup for discovery, then click through to PubChem for detailed data.

Try Element-Based Search

Experience the revolutionary way to discover chemical compounds. No formulas needed — just select elements.

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