v3.26.1
Document and Entity Information - shares
 3 Months Ended
Mar. 31, 2026
Jun. 02, 2026
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2026  
Document Fiscal Year Focus 2026  
Document Transition Report false  
Entity File Number 001-43251  
Entity Registrant Name Avalyn Pharma Inc.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 45-2463191  
Entity Address, Address Line One 105 W First Street  
Entity Address, City or Town Boston  
Entity Address, State or Province MA  
Entity Address, Postal Zip Code 02127  
City Area Code 206  
Local Phone Number 707-0340  
Title of 12(b) Security Voting Common Stock, $0.001 par value per share  
Trading Symbol AVLN  
Security Exchange Name NASDAQ  
Entity Current Reporting Status No  
Entity Central Index Key 0001540171  
Current Fiscal Year End Date --12-31  
Entity Ex Transition Period false  
Entity Small Business true  
Entity Filer Category Non-accelerated Filer  
Entity Interactive Data Current Yes  
Entity Emerging Growth Company true  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   44,333,095
Document Fiscal Period Focus Q1  
Amendment Flag false