self.mp3
Set up your bucket
self.mp3 keeps your music in a storage bucket of your own, at Backblaze. You make it once, in about ten minutes, and every device you sign in to finds it by itself after that.
It is easiest on a computer: Backblaze shows a long key once, and you copy it into self.mp3.
1. Make a Backblaze account
Enter an email address and press Get started for free. It does not have to be your Google one.
Backblaze emails a link to confirm the address. Open it in the same browser, within 15 minutes.
Choose a password and the data region nearest you, accept the terms, and press Create Account. The first 10 GB are free.
2. Create a private bucket
In the menu on the left, under B2 Cloud Storage, press Buckets, then Create a Bucket.
Every Backblaze user shares one list of names, so a plain one is often taken. Use letters, numbers and dashes, like selfmp3-yourname; Backblaze says at once if it is taken.
Choose Private, leave Object Lock off, and press Create a Bucket.
3. Keep only the last version
Backblaze keeps every old version of every file unless told otherwise, so a removed song or a replaced cover would go on using your 10 GB.
On the bucket you made, press Lifecycle Settings, choose Keep only the last version of the file, and save.
self.mp3 checks this when you connect. If it was missed it says so: set it, and press Connect again. Nothing needs making again.
4. Make a key for that bucket
In the menu on the left, press Application Keys, then Add a New Application Key. Not the master application key: it opens your whole account, and self.mp3 refuses it.
Name it anything with letters, numbers and dashes, like selfmp3.
Under Allow Access to Bucket(s), choose the bucket you made. A key for All is refused.
Under type of access, choose Read and Write.
Leave Allow List All Bucket Names unticked, and the file name prefix and duration empty. Press Create New Key.
5. Copy the two strings into self.mp3
Straight after Create New Key, Backblaze shows the keyID and the applicationKey. The applicationKey is shown only this once, so copy both before you leave the page.
In self.mp3, on Where it lives — the page after your first Google sign-in, or Settings › Account › Storage later — paste the keyID into Key ID and the applicationKey into Application key, and press Connect.
Lost the applicationKey? Make another key the same way. The old one can be deleted.
The key goes to self.mp3’s sign-in service, sealed; no device keeps it. Your other devices need nothing more than the same Google sign-in.
6. Before a big first import: raise the daily limits
Backblaze limits what a bucket does each day, under Caps & Alerts. Past a limit it stops the bucket until midnight GMT (5 pm Pacific); self.mp3 says so, and carries on by itself afterwards.
A first import of hundreds of songs is the usual way to reach one. To avoid the wait, press Edit Caps, raise the transaction limits or choose No Cap, and press Update Caps. A change takes up to ten minutes.
Since May 2026 Backblaze charges nothing for requests. Storage past 10 GB, and downloads past three times what you store, do cost; keep a cap on those if you want a ceiling.
If self.mp3 says…
- Backblaze does not know that key… Copy both strings again, whole, with no spaces at either end — or make a new key (step 4).
- That key opens every bucket on the account… Make a key for your one bucket rather than All (step 4).
- The key needs Read and Write on the bucket… Make a new key with Read and Write (step 4).
- This bucket keeps every old version of a file… Choose Keep only the last version of the file on the bucket, then Connect again (step 3).
- Storage allowance used up… Raise the limit under Caps & Alerts, or wait for midnight GMT (step 6).