For macOS 26 and later
Open the CSV that’s too big for everything else.
Rowscope shows the first rows of a 2 GB file in a fifth of a second, scrolls all 25 million of them, and never loads the file into memory. The file you open is never changed.
No account, no tracking
Reads what you have
- .csv and .tsv
- Comma
- Semicolon
- Tab
- Pipe
- UTF-8, with or without BOM
- Windows-1252
- LF, CRLF or CR
Everything a big file needs. Nothing it doesn’t.
Every pass over the file streams it in chunks, so sorting or searching 25 million rows stays under 20 MB of memory.
A viewer you can trust with the real data.
Exports from databases, logs and data dumps are rarely tidy. Rowscope is built for exactly those.
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Never changes your file
Viewing is read-only: no save, no autosave. Export writes only a new file you choose, and refuses to overwrite the one you opened.
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Flat memory
About 80 MB in use whether the file is 10 MB or 2 GB. Only the rows on screen are ever read and parsed.
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Detects the format
Comma, semicolon, tab or pipe; UTF-8 or Windows-1252. The toolbar overrides either, and turns the header row on or off.
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Forgiving with messy data
Stray quotes, ragged rows and invalid bytes are flagged on the row instead of stopping the file. Line breaks inside fields stay intact.
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Keyboard first
Arrow keys, Page Up and Page Down, Home and End, ⌘↑ and ⌘↓. ⌘F to find, ⌘G for the next match, ⇧⌘E to export.
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Private by design
No network access at all, no account and no analytics. Your data never leaves your Mac.
Measured, not promised.
A file 200 times bigger opens just as fast and uses almost the same memory. Most of that memory is the app itself.
- to the first row of a 2 GB file
- 0.19 s
- to index all 25 million rows
- 4.1 s
- memory in use afterwards
- 78 MB
- ever written to your file
- 0 bytes
| File size | 10 MB | 500 MB | 2 GB |
|---|---|---|---|
| Rows | 125,965 | 6,173,084 | 25,067,463 |
| First row on screen | 187 ms | 194 ms | 194 ms |
| Every row indexed | 0.28 s | 1.15 s | 4.1 s |
| Memory after indexing | 73 MB | 75 MB | 78 MB |
Measured on a Mac with M2 Pro and 16 GB of memory, release build, with the file already in the disk cache. Memory is the app’s footprint as macOS reports it. Sorting a numeric column of the 2 GB file takes 7.8 s; a full-text search, 6.9 s.
Open your biggest file today.
Rowscope runs on macOS 26 or later.
Coming soon to the Mac App StoreFrequently asked questions
Something else? Get in touch.
- Can Rowscope change or damage my file?
- No. Rowscope only reads the file you open: there is no save and no autosave. Export always writes a new file, and it refuses to use the open file as its destination.
- Which formats does it read?
- CSV and TSV files separated by commas, semicolons, tabs or pipes, encoded as UTF-8 (with or without a BOM) or Windows-1252. UTF-16 files are not supported yet.
- Does anything I open leave my Mac?
- No. Rowscope has no network access, no account and no analytics. See the privacy policy for the details.
- How big a file can it open?
- We test with files up to 2 GB and 25 million rows. Rowscope reads only what is on screen and keeps a small index, so memory barely changes with file size; larger files mostly take longer to index.
- What happens with a broken file?
- It still opens. A stray quote, a ragged row or an invalid byte is flagged on that row, and an unclosed quote is reported with the row where it starts.
- Will it take over my CSV files?
- No. Rowscope offers itself as an alternative for CSV and TSV files and never replaces your default app. To make it the default, use Get Info in the Finder.
- Can I edit cells?
- No, Rowscope is a viewer. To reshape a file, export the columns and rows you want to a new file, with a different delimiter, encoding or line endings if you need them.
- Does it open Excel or Numbers files?
- No. Rowscope opens plain-text CSV and TSV files. Save a spreadsheet as CSV first.
- Which Macs does it run on?
- Any Mac that runs macOS 26 or later.