SA Score
Synthesizability Assessment
Know What’s Possible Before You Synthesize
How SA Score works
Comprehensive Synthetic Feasibility Analysis
Reaction Logic & Complexity
Assesses step efficiency and overall feasibility.
Building Block Availability
Confirms that proposed routes rely on commercially available materials.
Cost Considerations
Accounts for starting material prices to recommend the most cost-effective pathways.
High-Throughput Screening
for Large Libraries
ChemAIRS evaluates hundreds of thousands of molecules in hours, ranking them based on synthetic accessibility.
This means you can input 100,000 molecules for overnight screening and by morning, you can read the results with your coffee.
SA Score is Validated
by Industry Experts
In a 1,346-molecule study, ChemAIRS matched Merck’s expert synthesis team, demonstrating industry-leading accuracy.
AI-driven assessments identified intermediates that human experts overlooked, improving robusticity of research and efficiency.
Know which molecules can actually be made - before you commit to lab time.
Most synthetic accessibility tools score molecules based on structural features alone. They flag complexity, but they cannot tell you whether a synthesis route actually exists. ChemAIRS SA Score is trained directly on the real shortest synthesis step counts.
0.701
Pearson correlation with real synthesis steps - the highest of any model benchmarked
16,400
Synthesizable candidates with specific routes identified from 20,000 selected
1M
Molecules evaluated in ~30 minutes with Fast Mode - practical for overnight screening
Trained on 1.5M+ drug-like molecules · time-split validation · post-2023 test set
We tested ChemAIRS SA score on 1.5 million drug-like molecules and validated on a post-2023 held-out test set. The result is a Pearson correlation of 0.701 with real synthesis steps - the highest of any model benchmarked, ahead of other commonly used SA Scores and SC Scores (structural complexity scores).
In a virtual screening scenario selecting 20,000 molecules for follow-up, ChemAIRS returned 16,400 synthesizable candidates with specific routes identified. ChemAIRS Fast Mode can evaluate one million molecules in approximately 30 minutes, making it practical for overnight screening at scale. For cases requiring higher accuracy, ChemAIRS full retrosynthetic reasoning provides route-level feasibility with concrete synthesis suggestions.
