KopiaLens

I've backed up my own machines with Kopia since January 2025 - about 5 TB across two repositories. It's a great backup engine, but it couldn't quickly answer the questions I kept asking: what does each folder really cost after deduplication, which snapshots still hold this file, and why did the repository grow so much last night? KopiaLens started in June 2026 as a way to answer those for myself, and it found 400+ GB of junk in my own backups, which I got back.

It grew into a full backup app. KopiaLens creates repositories, runs backups on a schedule, restores files and handles maintenance, and it works on the repositories people already have, so KopiaUI and the kopia CLI keep working alongside it. Every view reads an index that KopiaLens builds on your own machine (Parquet files read by DuckDB), so searching 19 million file versions takes about a second.

Version 1.0 came out on 30 October 2026, as a desktop app for Windows, macOS and Linux (a Tauri shell around the local web interface), a Docker image and a Home Assistant add-on. Backing up, restoring, search and every analysis view are free with no account; Pro adds the tools that remove junk from inside old backups. I also built the licensing behind it (offline licence keys, sold through Polar) and the kopialens.com website, which reuses this site's visitor-alert system.

• Real folder sizes after deduplication - what each folder actually costs in the repository.
• Find any file in any snapshot, with every version of it.
• Churn view - what grows each night, and where.
• Shows the folders on your disks that no backup covers.
• Pro: remove junk files and folders from old snapshots without losing the rest of their history.
• Scheduled backups, restore, maintenance and policies, on repositories you already have.
• Desktop app for Windows, macOS and Linux, plus Docker and a Home Assistant add-on.