Large CSV viewer
On-deviceThis page always downloads the big-file engine, even for a small file — the engine is what reads the file from disk. It downloads once and then stays on your device.
The viewer opens a CSV with a database engine that reads it from disk rather than loading it into memory, so a file of several hundred megabytes opens without the tab running out of room. It shows one page of rows at a time and tells you which rows you are looking at and how many there are altogether — it never quietly shows you part of a file as though it were all of it. Nothing about your file is uploaded.
About this tool
What you provide
- One CSV or TSV file.
What you get
- One page of up to 100 rows at a time, from anywhere in the file.
- The exact range of rows on screen and, once counted, how many rows the whole file has.
Limits
- Shows 100 rows per page — the file is never loaded or rendered all at once.
- Reading the file needs a one-time database-engine download of about 7 MB, downloaded even for a small file because the engine is what reads it from disk.
- The file is opened as a live view rather than copied into memory, so turning to a page deep inside a very large file takes about a second.
- Everything runs on your device and nothing about your file is uploaded.
How to use it
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Choose a CSV file
Tap “Choose a CSV file” or drop a .csv or .tsv file onto the dashed area.
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Download the engine
Tap “Download engine (~7 MB · one time)” — it downloads once and stays on your device for every file after that.
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Open the file
Tap “Open this file” to open it as a live view and read the first page of rows.
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Page through the rows
Use “Previous page” and “Next page” to move through the file 100 rows at a time — the range shown always says exactly which rows you are looking at.
Frequently asked questions
Why does this page ask me to download an engine even for a small file?
The viewer always uses the same database engine to read your file, whatever its size — the download happens once, then stays on your device for every file after that.
Why can't I see the whole file at once?
A file with millions of rows would overwhelm the tab if it were all rendered at once, so the viewer shows 100 rows at a time and always says which rows you are looking at and how many rows the file has in total.
Why is turning to a page deep inside a huge file slower than the first page?
The file is opened as a live view read straight from disk rather than copied into memory, so the first page opens almost instantly and a page deep inside a very large file can take around a second.
Does opening my file upload it anywhere?
No. The file is read on your device by the downloaded engine, and nothing about it is sent to a server.