A native Backblaze B2 GUI for iPhone, iPad & Mac
Cost-effective storage with an S3-compatible API. Universal S3 Client connects over the S3 API — browse buckets, transfer files and share presigned links, free and open source.
https://s3.{region}.backblazeb2.com
facts
Backblaze B2 at a glance
- endpoint
- https://s3.{region}.backblazeb2.com
- auth
- Application Key ID · Application Key · Region
- regions
- us-west-001, us-west-002, eu-central-003
- storage
- around $6/TB/month (2026)
- egress
- free daily allowance, free via Cloudflare
- Among the lowest $/TB prices
- Free egress through Cloudflare
- Native and S3 APIs side by side
setup
Get your Backblaze B2 access keys
Credentials are created in the Backblaze account — here's the exact path:
- 1
Log in to your Backblaze account and open "Application Keys".
- 2
Click "Add a New Application Key" — scope it to a single bucket or all buckets.
- 3
Copy the keyID and applicationKey shown once; the S3 endpoint for your account (with its region) is shown on the same screen.
- 4
Add Backblaze in Universal S3 Client with the key pair and your region.
Console: https://secure.backblaze.com/
good to know
Before you connect
The master application key does not work with the S3-compatible API — create a standard application key instead.
Very old B2 buckets (created before the S3 API existed) may not be reachable over S3; recreating the bucket fixes it.
features
What you can do with Backblaze B2
- Browse Backblaze B2 buckets and folders with breadcrumbs, list or grid view, and image thumbnails.
- Upload from your photo library or files with multipart transfers and a real progress bar.
- Generate time-limited presigned URLs to share private objects with anyone.
- Preview and edit JSON, YAML, CSV and text files in place — changes save back to the bucket.
faq
Backblaze B2 — frequently asked
+ Does Backblaze B2 work with S3 apps?
Yes — B2 exposes an S3-compatible endpoint per region (https://s3.{region}.backblazeb2.com). Universal S3 Client connects with a standard application key from iPhone, iPad or Mac.
+ Why doesn’t my B2 master key work?
Backblaze’s master application key is excluded from the S3-compatible API by design. Create a new application key under Application Keys — those work with any S3 client.
+ How do I find my B2 region?
It’s embedded in the S3 endpoint shown next to your application keys — for example us-west-002 or eu-central-003. Pick the same region when adding B2 in the app.
+ Is B2 good for backups managed from a phone?
B2’s low storage price makes it popular for backups, and the app lets you verify, browse and retrieve backup files on the go — including previewing config files and downloading archives.
related
Also worth a look
The free Backblaze B2 client for your pocket
Install the app, paste your Backblaze B2 keys, and manage your buckets from anywhere.