# Back up to Backblaze B2

> To back up to Backblaze B2, make an application key with Read and Write access to a bucket in Backblaze, then paste its keyID and applicationKey into Post Once under "Back up to". Post Once saves each new post to a Post Once folder in that bucket, with a caption file beside it.

Post Once help center, Backups. Source: https://postonce.com/help/back-up-to-backblaze-b2. Last updated 2026-10-25.

## Make a key in Backblaze

1. In your Backblaze account, open **Application Keys** and add a new key.
2. Pick the bucket for your backups and choose **Read and Write**.
3. Copy the **keyID** and **applicationKey**. Backblaze shows the application key only once.

## Connect it in Post Once

1. Open **Bridge** and press **Connect** next to **Backblaze B2** in the **Back up to** card, or pick it under **Also back up to (optional)** when you sign up.
2. In **Connect Backblaze B2**, paste the **keyID** and **applicationKey**.
3. Fill in **Bucket name (optional)** only if your key works on every bucket.
4. Press **Connect**. Post Once checks the key by saving a small "About this folder.txt" file in the bucket.

## Where your posts go

Everything goes in a **Post Once** folder in your bucket, sorted by account and month:

```
your-bucket/
  Post Once/
    Instagram @yourhandle/
      2026-10 October/
        2026-10-12 Fifteen minute tomato pasta.mp4
        2026-10-12 Fifteen minute tomato pasta.txt
```

Each post has a .txt file beside it with the caption and a link to the original post. More in [back up every post](https://postonce.com/help/set-up-backups).

Under the connected row, **Open Backblaze** opens your bucket list in Backblaze, and the **Save** switches choose which kinds of posts to keep.

## Cost

Storage is billed by Backblaze to you. B2 is one of the cheapest places to keep a growing video archive. Our [comparison of cloud storage for social media backups](https://postonce.com/blog/cheapest-cloud-storage-social-media-backup) has the numbers.

## Frequently asked questions

### Is my Backblaze key safe?

Post Once encrypts the key before storing it and deletes it when you disconnect Backblaze B2. Give the key access to one bucket only, so it can do nothing else in your account.

### Why does it say the key cannot read and save files?

The key was made without write access. In Backblaze, make a new application key with "Read and Write" access, then connect again.

### Can I use a key that works on all my buckets?

Yes. Then fill in Bucket name (optional) so Post Once knows which bucket to use.