View Parquet, Excel & binary files online — no upload
Open binary data files — Parquet, Excel, Arrow, MessagePack, CBOR, Protobuf, BSON, gzip — as a readable JSON tree or table. Everything decodes locally in your browser; the file never leaves your machine.
Open a binary file in your browser
Most data viewers make you upload a file to a server. Yellorn doesn't. Drag a binary file onto the editor — or onto the + button to open it in a new tab — and it's decoded locally, in a background worker, into a JSON preview you can read, search, and convert. The file never leaves your machine.
The format is detected from the file extension, so there's nothing to configure — just drop and read.
What you can open
- Parquet and Arrow / Feather — columnar data becomes an array of row objects.
- Excel (.xlsx / .xlsm / .xls) — one sheet becomes a row array; a multi-sheet workbook becomes an object keyed by sheet name. Dates read as ISO strings.
- MessagePack, CBOR, and BSON — decoded to whatever they hold (an object, an array, or a stream of records).
- Protobuf — decoded without the
.protoschema, so fields appear keyed by their field number. - gzip — decompressed to its underlying text (gzipped JSON comes back as JSON).
Whatever the container, the short version is the same: you get clean, browsable JSON.
Then explore, search, and convert
Once a file is open you have the full editor: the tree, graph, and table views; JMESPath search to query deep into the data; and one-click conversion to JSON, CSV, YAML, and more.
Binary formats are read-only: you're viewing a decoded snapshot, so you can convert the contents out to a text format, but Yellorn doesn't write binary files back.
Large files show a preview
Very large files are capped to keep the editor responsive. When that happens, a notice reads “Large file: showing the first N of M rows” so you always know you're looking at a preview, not the whole dataset.
Frequently asked questions
How do I open a Parquet file online without uploading it?
Drop the .parquet file onto Yellorn. It decodes the file locally in a background worker and shows the rows as a sortable table or a JSON tree in your browser. The file never leaves your machine — nothing is uploaded to a server.
Which binary file formats can Yellorn open?
Parquet, Apache Arrow/Feather, Excel (.xlsx/.xlsm/.xls), MessagePack, CBOR, BSON, Protobuf, and gzip. Each is decoded to a browsable JSON preview that you can search, view as a tree or table, and convert to a text format.
Can I open an Excel file without Excel installed?
Yes. Drop an .xlsx, .xlsm, or .xls file and Yellorn reads it in your browser — a single sheet becomes a row array, a multi-sheet workbook becomes an object keyed by sheet name, and dates come back as ISO strings. No Excel, no upload.
Can it decode Protobuf without the .proto schema file?
Yes. Without the schema, Protobuf can't recover field names, so Yellorn decodes the message with fields keyed by their numeric field number. You still see the structure and values — enough to identify the payload and convert it out.
Can I edit or save a binary file?
No. Binary formats are import-only: you're viewing a decoded snapshot, so Yellorn never writes the binary back. You can convert the decoded contents out to JSON, CSV, YAML, or another text format in one click.
Related
Where to go next
Try a fix in the editor or browse more articles.