---
title: Why do I see empty files in my blob storage export?
description: Empty files in a Langfuse blob storage export are expected and normal — this article explains why they appear and how to handle them in downstream pipelines.
tags: [platform, integration]
---

# Why do I see empty files in my blob storage export?

The [blob storage integration](/docs/api-and-data-platform/features/export-to-blob-storage) exports one time window of data per run, writing a file per table (for example `observations_v2/` and `scores/`). If you find empty files in your bucket, this is expected behavior — here's why, and how to handle it.

Empty files are expected and normal; they are not an error or a sign of data loss. A given time window may contain data for some tables but not others (for example, observations but no scores in that window). When a table has no data for a window, the exporter may still write a file for it, and that file will be empty.

What an empty file looks like depends on the configured file format:

| Format      | Empty file looks like                                                          |
| ----------- | ------------------------------------------------------------------------------ |
| **Parquet** | A valid Parquet file with schema metadata but zero rows (not a zero-byte file) |
| **JSON**    | A file containing `[]`                                                         |
| **JSONL**   | An empty file                                                                  |
| **CSV**     | A header row only (or empty)                                                   |

Build downstream pipelines to tolerate empty files:

- Treat an empty file as "no data in this window for this table," not as a failure, and don't alert on its presence.
- Don't assume every window contains a file for every table.
- Process the objects listed in the completed run's manifest instead of deriving filenames or listing table directories.

See [Process exports](/docs/api-and-data-platform/features/export-to-blob-storage#consume-exports) for the bucket layout and manifest workflow, or the [export field reference](/docs/api-and-data-platform/features/blob-storage-export-fields) for schemas.

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