When you request a data export from Bluesky, the result comes in the CAR Content Addressed Archive format. Many users are surprised by how large or small their export file turns out to be. The size depends directly on your account activity: the number of posts, reposts, likes, and followed accounts all contribute to the final file. This article explains what determines your CAR export size, what you can expect based on common account profiles, and how to interpret the contents of the archive.
Key Takeaways: Bluesky CAR Export File Size
- Settings > Account > Export Data: Initiates the CAR archive download of your account’s repository
- Repository data only: The CAR file contains your posts, likes, reposts, follows, and profile metadata but does not include direct messages or media blobs
- File size scales with activity: A light user with under 100 posts may get a 2–5 MB file while heavy users with thousands of interactions can see files over 100 MB
What Determines the Size of a Bluesky CAR Export
The CAR export is a snapshot of your Bluesky repository. This repository stores every action you have performed on the service in a structured format. Each post, repost, like, follow, and block creates a record called a commit. The CAR file contains all these commits compressed together.
The main factors that influence file size are:
- Post count and length: Each text post adds a small record. Longer posts with embedded links or images add slightly more data because the link metadata is stored.
- Reposts and likes: Each repost and like creates its own commit. A heavy user who likes hundreds of posts a day will accumulate these quickly.
- Follow and block lists: Every account you follow or block is recorded. Following thousands of accounts adds noticeable size.
- Profile metadata: Your display name, bio, avatar reference, and banner reference are stored once and updated only when you change them.
- Media blob references: The CAR file does not include the actual images or videos. It stores a reference hash for each blob. The actual media files are available separately through the blob export feature.
Because media files are excluded, the CAR export is usually much smaller than the total storage your account uses on Bluesky servers. A user with many large images may have a small CAR file but a large blob export.
Expected File Sizes for Different Account Types
The table below shows realistic file size ranges based on account activity levels. These figures are approximations and may vary based on the specific content of your commits.
| Account Profile | Activity Level | Typical CAR Export Size |
|---|---|---|
| New or minimal user | Under 50 posts, under 100 likes, under 50 follows | 1–3 MB |
| Casual user | 100–500 posts, 500–2000 likes, 100–500 follows | 5–20 MB |
| Active user | 1000–5000 posts, 5000–20000 likes, 500–2000 follows | 20–80 MB |
| Power user or bot | Over 10000 posts, over 50000 likes, over 5000 follows | 80–250 MB |
How to Request and Download Your Bluesky CAR Export
- Open Bluesky Settings
Click your profile avatar in the top-right corner and select Settings from the dropdown menu. - Go to Account Settings
In the left sidebar, click Account. - Scroll to the Export Data Section
Look for the heading Export my data. You will see a button labeled Export Data. - Click Export Data
Bluesky will generate a CAR file of your repository. Depending on your account size, this may take a few seconds to several minutes. - Download the File
Once the file is ready, your browser will download a file named likebluesky-export-username-2025-01-01.car. The exact name depends on your handle and the export date.
After downloading, you can inspect the file using the @atproto/pds command-line tools or third-party CAR viewers. The file is not human-readable as plain text. You need a tool that understands the AT Protocol repository format.
Common Misconceptions About CAR Export Size
“My CAR export is too small — something is missing”
A small CAR file does not mean your data is incomplete. If you have fewer than 100 posts and limited interactions, a 2 MB file is normal. The export includes all your commits. You can verify by checking the commit count using a CAR inspection tool. Compare the number of commits to your visible post count. Each post, like, and follow adds one commit. If the numbers match roughly, your export is complete.
“My CAR export is huge — it must contain media files”
The CAR file does not store media blobs. It stores only references to them. A large CAR file indicates a high volume of text-based commits. If you have thousands of reposts and likes, those are the main contributors. Media files are exported separately through the blob export option in the same Settings section.
“The export size is different each time I download it”
This is expected. Each export is a snapshot of your repository at that moment. If you post, like, or follow new accounts between exports, the new file will be larger. The size difference reflects your recent activity.
Bluesky CAR Export vs Blob Export: What Each Contains
| Item | CAR Export | Blob Export |
|---|---|---|
| Text posts and replies | Yes | No |
| Reposts and likes | Yes | No |
| Follow and block lists | Yes | No |
| Profile metadata | Yes | No |
| Images and videos | No (only references) | Yes (actual files) |
| Direct messages | No | No |
If you need both your activity history and your media files, you must download both exports separately. The CAR export alone does not allow you to reconstruct your feed with images attached.
Conclusion
The size of your Bluesky CAR export directly reflects your account activity. A light user with minimal interactions will see a file under 5 MB, while power users can expect files over 100 MB. You can request the export at any time from Settings > Account > Export Data. To get a complete backup including images, also download the blob export from the same page. For inspecting the CAR file, use the AT Protocol CLI tools available on GitHub.