Online Tool Store
Parquet Viewer
Check whether a .parquet file has a valid header and footer, and see its file size. Runs entirely in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
A .parquet file always starts and ends with the 4 ASCII bytes "PAR1" — checked directly against your file's bytes, not simulated.
How it works
- Choose a .parquet file.
- The tool reads the first and last 4 bytes and checks for the "PAR1" magic marker.
- See file size and validity — full row/column preview is planned but not yet built.
FAQ
What does the validity check actually verify?
Every real Parquet file starts and ends with the 4-byte ASCII marker "PAR1" — this tool reads those exact bytes directly from your file and confirms they're present, a genuine structural check, not a simulation.
Why can't I see the actual rows and columns yet?
Parquet stores data in compressed, Thrift-encoded column chunks — decoding that fully needs a dedicated binary-parsing library, which isn't wired up in this frontend-only release. This tool is upfront about that rather than faking a data preview.
What is Parquet used for?
A columnar storage format popular in data engineering and analytics (Spark, Pandas, data lakes) — efficient for reading specific columns out of large datasets without scanning entire rows.
Is my file uploaded anywhere?
No — the file is read entirely in your browser. Nothing is sent to a server.
How we compare
| Feature | Online Tool Store | Python/Pandas | Desktop data tools |
|---|---|---|---|
| Quick "is this file valid" check | ✓ | Requires writing a script | Requires installing an app |
| No install | ✓ | Requires Python + pandas | Requires a desktop app |
For a fast sanity check that a Parquet file isn't corrupted before opening it in a full data tool, this is a quick first step.