Slipstream

The problem

Getting files from an external drive to cloud storage is two manual steps and a lot of waiting.

Sync clients hate external drives

macOS removed the API that let Dropbox and OneDrive watch external volumes. Reconnecting a drive triggers a full re-scan, duplicates, or silent deletes.

Browser uploads are fragile

No resume after a dropped connection. Chrome caps folder uploads. For anything in gigabytes, a single Wi-Fi blip costs you the whole transfer.

Copy-first eats your disk

The "reliable" path — drive → laptop → sync client — chews through 256–512 GB of internal storage in batches and lands you in a manual cleanup loop.

What Slipstream does

Plug in a drive, pick a cloud destination, hit Start. The pipeline is designed for transfers measured in tens of gigabytes.

2 GB sliding windowFiles are buffered to a small local cache, uploaded, and purged. Your internal disk is never the bottleneck.

Byte-perfect SHA-256Every file's hash is computed on read and verified against the destination. Integrity is auditable, not trusted.

ResumableDrive disconnect, network blip, or app crash — Slipstream picks up exactly where it left off, no duplicates created.

Destination dedupRe-running over an already-populated folder skips files that are already there. You won't end up with 14 of one photo.

Retry with backoffTransient 5xx and connection blips are retried automatically. A single Wi-Fi hiccup doesn't fail your transfer.

Honest progress"X uploaded, Y skipped, Z failed" — never just "completed". You always know what actually moved.

What Slipstream is not

For the avoidance of doubt:

Not a sync client. There's no continuous background watcher; Slipstream runs only while you have it open.
Not a backup service. We don't operate a server. Files go from your machine straight to your cloud account.
Not a place we see your data. There is no Slipstream analytics endpoint, telemetry, or back-end. Read the privacy policy for the full breakdown.