The CSV editor
the Mac never had.
A CSV viewer and editor for Mac. Notepad++ for CSV, on steroids. Tabulay opens a CSV as the file wrote it, millions of rows included, and lets you edit it from the keyboard. The editor is free. Tabulay Pro adds the steroids: charts, dedupe, compare and SQL.
Notepad++ never shipped for the Mac. Tabulay was made for it.
On a Mac, a CSV ends up in a spreadsheet, made for numbers you type, or in a text editor, which has no columns. Numbers stops at 1,000,000 rows. Excel stops at 1,048,576 and, by default, drops leading zeros and turns values into dates. Tabulay opens millions of rows as the file wrote them.
A Numbers table holds up to 1,000,000 rows and 1,000 columns.
A Google Sheets spreadsheet holds up to 20 million cells, and lives in Google Drive.
Source: Google
Excel keeps 15 significant digits. In a 16-digit ID or card number, the last digit becomes a zero.
Source: Microsoft
By default, opening a CSV in Excel drops leading zeros and turns some values into dates. In 2020, 27 human genes, SEPT1 and MARCH1 among them, were renamed partly for this reason.
Sources: Microsoft, Nature Genetics
Notepad++ runs on Windows. It has never had an official Mac version.
Sources: Notepad++, its author, May 2026
Tabulay is built on one rule: never change a value you didn’t ask to change. Opens as written. Edits like text. Answers like a database.
Opens as written. Changes nothing you didn’t.
The grid draws each value as the file wrote it: no number format, no date conversion, no scientific notation. Leading zeros, 16-digit IDs and gene names stay as they are. Semicolons, decimal commas, dd/MM/yyyy dates, an old encoding: Tabulay detects them, and File ▸ Open with Options… shows the result before the file opens.
Detected, then shown
Open with Options (⇧⌘O) shows the delimiter, encoding (UTF-8 or Windows-1252), header row, decimal separator and date format, each with a live preview.
European numbers add up
Amounts written -1.234,50 or -12 480,00 are numbers: they sort, filter and total to the cent, and are saved as written.
Excel workbooks Pro
Open with Options lets you pick a sheet and say whether its first row is the header; Open takes the first visible sheet. Values come out plainly: numbers without grouping or currency symbols, dates as ISO. ⌘S asks where to save the CSV: the workbook is never written.
Saved exactly. Byte for byte.
When you save, the rows you didn’t touch are copied from the original byte for byte: same delimiter, same quotes, same encoding, same line endings. Edited rows are written with the file’s delimiter, encoding and line endings, quoted only where needed. Add, delete, split, merge or compute a column, and every row is written that way. Open and save without edits, and the file is identical.
What your other tools expect
Semicolons, CRLF, Windows-1252, a byte order mark, line breaks inside quotes: whatever your bank, ERP or pipeline sent is what it gets back.
Refuses to damage
A character that can’t be written in the file’s encoding stops the save and names the value and its column, instead of being replaced by a question mark.
Safe writes
Tabulay checks the free space, writes a complete new file, and swaps it in only when it’s done. A crash mid-save can’t leave half a file.
Every change is a step you can take back.
Each edit, replace, delete and cleanup is recorded as one named step. Undo, redo, or click any point in the History to return to it. Your file on disk isn’t touched until you save.
Named steps
The Edit menu says exactly what it will undo: Undo Replace in track, not just Undo.
History as a script
The whole session reads as a pipeline you can copy and keep next to the file, to show what was done.
Preview, then one step
Find & replace, Normalize and Remove Duplicates show the exact changes and their count first. Then the whole change is one step.
Edits like text. Free, for good.
Open the file, fix it from the keyboard, save it. Tabulay is built with AppKit, the framework behind Apple’s own apps: tabs, full menus, Dark Mode, Increase Contrast and VoiceOver. Every command is in a menu and in the command palette: press ⌘K on this page to feel it.
Keyboard first
⌘K finds any command, column or row. ⌘F finds text in every cell, and ⇧⌘F shows only the matching rows. The common commands have shortcuts.
Edit in place
Type to edit, paste from Numbers or Excel, fill down with ⌘D, insert and delete rows and columns. Tabulay can become the app that opens .csv and .tsv files in Finder.
Free, trial or not
Open, find, filter, sort, edit and save CSV and TSV files up to 2 GB, with the History, byte-exact saves, the column profile and card-number protection. No account, no time limit.
Click to filter. Or type SQL. Same rows.
Filter chips answer the everyday questions in two clicks: this country, that status, over this amount. Each chip is a line of SQL, so you can switch to the editor at any moment and pick up exactly where you were. Running your own SQL needs Tabulay Pro.
Right-click any value
Show only this value, hide it, or keep rows at least or at most this number or date. Filtered columns say so in their header.
Find, then filter
⌘F finds text across every cell. Turn on Matching rows only (⇧⌘F) and everything else steps aside.
Totals in exact decimals
Select a number column, decimal commas included, to see its sum, average and count in the status bar, with a warning when currencies are mixed. It adds up to 200,000 rows and says when it stops; SQL totals the whole file.
Know a column before you trust it.
Click a column and the inspector shows what’s really in it: its type, how much of it conforms, the range of a number column, a histogram or the most frequent values (click one to filter), and the exact values that don’t fit. Problems show up before they reach your report.
Try it: click a column header.
Two-line headers
Each header shows the column’s name, its type (date, dec(12,2), enum(5)) and how many values don’t fit it.
Issues with a next step
Each issue card shows examples and a next step: Normalize (Tabulay Pro) for values that don’t fit, Show or Filter for empty ones.
Column insights Pro
A box plot of a number column (percentiles, mean, standard deviation, outliers), its average or sum per category and over time, and the timeline of a date or text column. Over the rows in view, computed on your Mac; click a category to filter.
See the shape of your data. Then ask it a question.
The editor is free. Tabulay Pro adds eight power tools: charts for any column, duplicates and differences shown before anything changes, and a full SQL engine. A monthly subscription of $1.99, with all eight in a 14-day introductory free trial for eligible subscribers.
See duplicates before they’re gone.
Two plays of the same track by the same listener on the same day can both be real. So Tabulay compares every column by default, lists the duplicate groups before anything is removed, and warns you if you leave out the column it found to be the file’s ID.
Try it: untick the ID column.
What changed between two files, row by row.
Compare yesterday’s export with today’s, or your file with the one that came back from review. Rows are matched on an ID column, so a moved row isn’t a change, and every changed field shows its before and after.
Matched on your key
Pick the shared ID column, or compare by position when there isn’t one.
Every kind of change
Added, removed and changed rows, columns found in only one file, and IDs that appear twice.
Export the differences
Save the whole comparison as a CSV, to share or to keep with the audit trail.
Ask your file a question.
A full analytical SQL engine is built in. Your file is a table named after itself, or simply this. Group, pivot, rank, compute growth and percentiles on millions of rows, with no import step and no database to set up.
Queries tested on the demo’s sample files. Results computed from the full files.
Examples that know your columns
The Examples menu writes queries from your own file: totals and shares, top 3 per group, statistics, outliers, monthly growth, pivots.
Errors that help
Unknown column “amont”. Did you mean amount? A mistyped column name gets the closest match.
See the real plan
Explain shows how the engine will run your query, with timings on request. ~ matches regular expressions.
See every change before it happens.
Find & replace, split, merge, computed columns, normalize: each shows you the exact changes, and how many there are, before anything is touched. Then it all happens as one step you can undo.
Regular expressions, with groups
Match with a pattern, rebuild with $1, $2. Case-sensitive or not, one column or all of them.
Normalize without guessing
In a column written with decimal points, a stray -1.234,50 becomes -1234.50. 1,234 could be either 1234 or 1.234, so Tabulay leaves it and tells you.
Split, merge, derive
Split Lille, France into two columns, merge with a template like {track} by {artist}, or derive a column from an expression.
No million-row ceiling. Big files, open in seconds.
Tabulay doesn’t load your file into a grid. It indexes it: one quick pass notes where every row begins, then only the rows on your screen are parsed. The limit is in bytes, not rows. The figures below were measured on a file of 1.3 million rows.
to index 1.3 million rows1
to show the first rows1
to check the type of every value1
to save after an edit1
Mapped and indexed
macOS maps the file instead of copying it into memory, and one pass indexes every row. A row is parsed only when it’s shown or queried.
Every row checked
Tabulay proposes a type for each column from a sample, then checks every row in the background. The header counts what doesn’t fit.
2 GB, then read-only
Files up to 2 GB open for editing. Larger files still open, read-only, so you can look through them safely.
Can’t send your data. Not won’t. Can’t.
A Google Sheets spreadsheet holds up to 20 million cells, and lives in Google Drive.2 Tabulay has no network access at all. Mac App Store apps must declare what they’re allowed to do; Tabulay never asked for the network, so macOS blocks any connection it could try.
The developer does not collect any data from this app. That’s the label Tabulay carries on the Mac App Store.
No account
Nothing to sign up for, nothing to sign in to.
Feedback on your terms
Send Feedback opens your own mail app with a message you read before sending.
Card numbers, masked in the grid.
Exports from order, CRM or support tools sometimes hold card numbers. Tabulay finds them, shows only the last four digits in the grid, keeps copies off clipboard history, and warns you before a save or an export writes a column of card numbers in full.
Found by checksum
13 to 19 digits that pass the Luhn checksum and carry a card network’s prefix, even inside text such as “paid with…”.
Kept off the clipboard
Cells copied from the grid that contain card numbers stay on this Mac and are marked concealed, so clipboard history apps don’t record them.
Enforced by IT
Masking, clipboard protection, save warnings and memory-only working copies can be enforced with a configuration profile. Security overview
Made for the people who get the file.
If your week starts with an export, Tabulay is for you. A few of the questions it answers in a minute.
Developers and data
Extracts, pipeline outputs and logs, opened as they are and checked with SQL, with no database to set up.
Sales and marketing
CRM, campaign and survey exports from European tools, with semicolons and decimal commas. Amounts like -1.234,50 are numbers: they sort, filter and total, and save as written.
E-commerce and inventory
Order histories and stock files that outgrew the spreadsheet a year ago.
Research
Instrument output, gene lists and survey data, where an identifier must stay exactly as written.
Support and operations
Ticket and SLA exports that pivot tables struggle with.
IT and security
Files with card or personal data, handled on managed Macs with enforceable settings.
The editor is free. Pro is monthly.
Download Tabulay free: open, find, filter, sort, edit and save CSV and TSV files up to 2 GB (larger files open read-only). Tabulay Pro adds eight tools for $1.99 per month. Eligible subscribers get a 14-day introductory free trial, then the subscription renews monthly until cancelled.
Tabulay
The editor, free for good. No subscription required.
- Open CSV and TSV files up to 2 GB (larger ones read-only)
- Find, sort, filter chips, status-bar totals
- Edit, paste, insert and delete rows and columns
- Tabs, full menus and the ⌘K command palette
- Full history with undo and redo
- Byte-exact save
- Column profile and type checks on every row
- Card number masking and protections
Your files and your edits are always yours to save, whatever happens to the trial.
Tabulay Pro
A monthly subscription through the Mac App Store.
- Everything in Tabulay
- Column insights: spread, breakdowns, timelines
- Remove duplicates, with the groups shown first
- Compare two files, row by row
- SQL queries, with Examples
- Query plans
- Transform: find & replace, split, merge, computed columns
- Normalize decimals and dates
- Excel workbooks (.xlsx)
US price; the Mac App Store shows your local price. Eligible subscribers get 14 days free, then $1.99/month. Auto-renews until cancelled. Cancel at least 24 hours before the trial ends to avoid a charge. Manage or cancel in the App Store. Terms of Use · Privacy.
What to expect
First, the current Mac app and its eight Pro tools on a monthly subscription. Next, we plan Tabulay CLI and an MCP server for CSV: tools that existing AI agents could use to inspect files and run analysis.
Tabulay would provide the CSV tools, not a built-in AI model. Your assistant would interpret the question; Tabulay would execute the analysis. These connections are planned, not available. There is no release date. Their pricing and access are undecided and are not included in today’s subscription promise.
Questions, answered plainly.
When can I get Tabulay?
Now, on the Mac App Store.
What does it cost?
Tabulay is a free download. Opening, viewing, sorting, filtering, finding, editing and saving stay free. Tabulay Pro is $1.99/month for column insights, Remove Duplicates, Compare, SQL, query plans, Transform, Normalize and Excel workbooks. Eligible subscribers get a 14-day introductory free trial, then monthly billing begins automatically unless cancelled. Cancel at least 24 hours before the trial ends to avoid a charge. Subscription details.
Why not open my CSV in Numbers or Excel?
Keep them for what they’re made for: formulas, charts you lay out, numbers you type. Tabulay is not a spreadsheet, on purpose. Numbers stops at 1,000,000 rows. Excel stops at 1,048,576 and, by default, drops leading zeros and turns values into dates. Tabulay opens millions of rows as the file wrote them. The full comparison has the sources.
What does “Notepad++ for CSV” mean?
It’s a comparison, not an affiliation. Notepad++ runs on Windows and has never had an official Mac version. Tabulay works the way a good text editor does, with columns: it opens the file as it is, runs from the keyboard and stays out of the way. The editor is free. Tabulay Pro adds the steroids: column insights, Remove Duplicates, Compare and SQL, among eight features.
What does it need?
macOS 14 Sonoma or later.
How big a file can it open?
Files up to 2 GB open for editing, which is millions of rows. Larger files open read-only. Speed depends on the file and the Mac: on our 1.3-million-row test file, indexing took about a third of a second with a release build of the core engine.1
Will Tabulay change my file?
Only where you change it. Saving copies every untouched row byte for byte, and writes edited rows with the file’s delimiter, encoding and line endings, quoted only where needed. Adding, deleting, splitting, merging or computing a column rewrites every row that way. Opening and saving a file without edits leaves it identical.
Does my data leave my Mac?
The current Mac app has no permission to use the network, so macOS blocks any connection. There’s no account and no analytics. The App Store privacy label reads “Data Not Collected”. The planned CLI/MCP connection is separate: an external AI assistant may send data returned by tools to its provider.
Do I need to know SQL?
No. Filter chips, right-click filters, sorting and Find cover everyday questions without SQL, and they’re free. When you want more, the Examples menu writes SQL from your own columns for you to adapt, and running it needs Tabulay Pro.
Does it open Excel and Numbers files?
Tabulay Pro opens Excel workbooks (.xlsx): you choose a sheet and work on it like a CSV, and the workbook itself is never changed. Older .xls files and Numbers documents aren’t supported: export them as CSV or .xlsx first.
Is Tabulay PCI DSS compliant?
Standards like PCI DSS and ISO 27001 apply to organizations, not to apps, so no app can be “compliant” on its own. Tabulay helps you meet specific requirements, such as masking card numbers in the grid (PCI DSS 3.4.1) and truncating them before storage. The security overview maps each requirement.
Is the app available in French?
The app is in English for now. Its App Store page and this website are in English and French.
Windows or Linux?
Not planned. Tabulay is a Mac app through and through, built with the Mac’s own frameworks.
Who makes Tabulay?
Alain Deléglise, an independent developer in Lille, France, publishing as Expertise By Me. Questions go straight to him at hello@tabulay.app.
Open your biggest file today.
Free on the Mac App Store, with a 14-day free trial for eligible subscribers.
Download Tabulay1. Measured on a 207 MB, 1.3-million-row CSV file with a release build of Tabulay’s core engine, on a MacBook Pro, Apple M4 Max, 36 GB, September 2026. Actual times vary with the file and the Mac.
2. Google Drive Help: files you can store in Google Drive, checked September 2026.
The demos on this page are recreations of the app in a web browser, with fictional sample data: every name in it is invented.
Numbers is a trademark of Apple Inc. Google Sheets is a trademark of Google LLC. Notepad++ is a trademark of its author, Don Ho. Tabulay is not affiliated with Apple, Google or Notepad++.