Free, Secure, and Open-Source
Backup for Microsoft 365
The #1 open-source backup tool for Microsoft 365
What Corso Users Say
“Documentation is great... initial steps for setup are really useful.”
Microsoft 365 Administrator
"I liked the tool a lot. But once I connected with the team on Discord, I could see that this team really knows what they're doing. That made me a lot more confident."
Kias Hanifa, CTO, Fonicom
"Corso is a fantastic tool, especially the backend logic with Kopia that lets me run incremental backups"
See why Corso is a perfect fit for your Microsoft 365 backup and recovery needs.
Choice of Object Storage
Why Everyone Loves Corso
The Corso community provides a venue for M365 admins to share and learn about the importance of data protection as well as best practices around M365 secure configuration and compliance management.
- Community-led blogs, forums, and discussions
- Public and feedback-driven development roadmap
- All community contributions welcome
Corso provides secure data backup that protects customers against accidental data loss, service provider downtime, and malicious threats including ransomware attacks.
- End-to-end zero-trust AES-256 and TLS encryption
- Support for air-gapped backup storage
- Choice of backup storage provider and geo location
Corso, purpose-built for M365 protection, provides easy-to-use comprehensive backup and restore workflows that reduces backup time, improve time-to-recovery, reduce admin overhead, and replace unreliable scripts or workarounds.
- Constantly updated M365 Graph Data engine
- Purpose-built, flexible, fine-grained data protection workflows
- High-performance backup and recovery data movers
Corso, a 100% open-source tool, provides a free alternative for cost-conscious teams. It further reduces storage costs by supporting flexible retention policies and efficiently compressing and deduplicating data before storing it in low-cost cloud object storage.
- Free forever OSS with no licensing costs
- Client-side compression and deduplication
- Support for S3-compliant storage including AWS Glacier IA
Frequently Asked Questions
Corso has both native binaries and container images for Windows, Linux, and macOS.
Corso currently supports OneDrive and Exchange. Support for Teams and SharePoint is in active development and is therefore not recommended for production use.
Corso supports any S3-compliant object storage system including AWS S3 (including Glacier Instant Access), Google Cloud Storage, and Backblaze. Azure Blob support is coming soon.
If you are unable to find an answer in our documentation, please file GitHub issues for bugs or join the Discord community.
Corso's source code is licensed under the OSI-approved Apache v2 open-source license.
Start Protecting Your
Microsoft 365 Data!
Corso is Free and Open Source
Follow our quick-start guide to start protecting your business-critical Microsoft 365 data in just a few minutes.Get Started