Vivaldi

Vivaldi combines tab stacks, workspaces, notes and a feed reader with ad and tracker blocking. On desktop, open Settings > Sync and use an account login plus a separate encryption password. The guide says that password is used locally and is not sent to Vivaldi. Save a Backup Encryption Key while access still works.

Sync is not a guaranteed backup. Reset Remote Data deletes the server copy; a device with local data can upload it again. If no device retains the data and neither the encryption password nor a backup key is available, resetting can lose the synced copy. The guide also requires a separate account for each profile being synced.

The browser is free. Its policy separately describes a daily active-profile count and optional search suggestions sent to the selected search engine. If crash-log sharing is enabled, Vivaldi says the full report may contain passwords or page content from memory. It says it removes the full report after processing and retains the extracted stack trace and active page URL for sixty days. Those settings sit alongside encrypted sync and local cookie controls.