📱 Tutorial · 7 min read

How to Open a CSV File on iPhone

Tap the file in the Files app and you get text, because nothing on iOS claims the .csv extension. Numbers does: open Numbers, tap Browse in the document manager, and tap the .csv thumbnail. The rows land in a real table. If the columns land in the wrong place, the fix lives in Table > Adjust Settings, and Apple is explicit that you have to do it before you edit a single cell.

This page is the phone-sized version of the same problem people hit on a laptop: the file is fine, the reader guessed wrong. Below are the three taps that import it, the five settings that fix a bad import, and the one move that cannot be undone.

Why a CSV arrives as text on an iPhone

A CSV is not a spreadsheet. It is lines of text with commas between the fields, and RFC 4180 registers it that way: the media type name is text, the subtype csv. Section 2 of that document defines each record as sitting on its own line, delimited by CRLF, with fields separated by commas.

So on a phone the bytes are readable everywhere and interpretable nowhere. A text preview shows you the commas. Turning those commas into columns is a job for an app that knows how to import delimited text, and on iOS that app is Numbers, which Apple ships free and which explicitly imports "Excel spreadsheets, as well as delimited or fixed-width text files".

Open the CSV in Numbers

Apple's documented path is three steps and does not involve the Files app:

1. Open Numbers and go to the document manager.
2. Tap Browse and find the file, wherever it lives: on the iPhone, iCloud Drive, a connected server, or another storage provider.
3. Tap the thumbnail of the .csv file.

That is the same route Numbers uses for .xls and .xlsx files. If the table that appears looks right, you are done: the file is now a Numbers spreadsheet and you can sort, total and edit it like any other.

If a file was emailed to you, save the attachment to Files first. The import starts from inside Numbers, so the file has to exist somewhere the document manager can browse to.

When the columns are wrong: the Delimited tab

A single column full of commas, or a first row that swallowed the header, means Numbers guessed the separator wrong. Fix it like this, per Apple's instructions:

1. Tap anywhere in the table to select it.
2. Tap the formatting button, then Table, then Adjust Settings.
3. Tap the Delimited tab.
4. Tap one or more delimiter options to separate values, or type a custom delimiter. Apple defines a delimiter as the character that defines column breaks.
5. Tap Update.

The same panel holds four more switches that solve most remaining messes:

• Text Encoding. Pick the encoding the file was actually written in. Accented letters turning into symbols is an encoding mismatch, not a broken file, and the guide to CSV file encoding covers how to identify the right one.
• Text Qualifier. The character that marks where a value begins and ends, normally the double quote. If your file wraps values containing commas in quotes, this is what keeps "Smith, John" in one cell instead of two.
• Treat Consecutive Delimiters as One. Turns runs like a;;;b into one break instead of three empty columns.
• Transpose Rows and Columns. Flips the table on import, which is what you want when a report was exported sideways.

If the file has no delimiter at all and the columns are defined by character counts, it is a fixed-width file, and that gets its own tab.

Fixed-width files: the other tab

Bank statements, payroll exports and a lot of mainframe output are fixed-width rather than delimited. On iPhone, open Table > Adjust Settings > Fixed Width and:

• Tap in the header row to add a new column break.
• Drag the arrows in the column address bar to change how many characters each column holds.
• Drag an arrow up and out of the address bar to merge columns.
• Set Text Encoding if the characters are wrong, and tap Update when the preview looks right.

The rule that costs people an hour

Apple states it plainly: you can't adjust import settings after you edit the imported table. Not "it is harder". The option stops being available.

So the order is import, check, adjust, then edit. If you already typed into the table and the encoding is still wrong, re-import the original file and set the options on that fresh copy, then copy your edits over. Nothing is lost except the minute it takes.

Getting the CSV back out of Numbers

Sharing works from the spreadsheet: tap Share, choose Export and Send, then pick CSV. Apple describes the result as cell contents shown as values separated by commas in the exported file. That wording matters: CSV carries values, not formatting, so bold text, fills and cell styles disappear, and a column that only looked like 001 because of a number format can come back as 1. If leading zeros or a date layout has to survive the round trip, the guide to keeping leading zeros in CSV shows the two fixes that hold.

Numbers also exports TSV, where cell contents are separated by tab stops. That is the better choice when the receiving system chokes on commas inside quoted values.

If the file is too big for the phone

Numbers is comfortable with a few thousand rows and unhappy with a million. If the import hangs or the table never finishes rendering, split the file first: the CSV splitter cuts by row count or file size in the browser, and the guide to CSVs that are too big for Excel explains what the real ceilings are and why they exist.

If you would rather check the file before importing it anywhere, drop it into the CSV analyzer: it reports the delimiter, the encoding, the column types and the row count it actually parsed, so a wrong guess by Numbers stops being a mystery.

Frequently Asked Questions

Sources

• Apple, Numbers User Guide for iPhone, "Import an Excel or text file on iPhone": the Browse path, the Delimited and Fixed Width tabs, Text Encoding, Text Qualifier, Treat Consecutive Delimiters as One, Transpose Rows and Columns, and the note that import settings cannot be adjusted after editing the imported table. Retrieved 2026-10-30.
• Apple, Numbers User Guide for iPhone, "Open a spreadsheet in Numbers on iPhone": Numbers imports .xls and .xlsx spreadsheets, delimited text files and fixed-width text files, from the iPhone, iCloud Drive, connected servers, third-party storage providers and external storage. Retrieved 2026-10-30.
• Apple, Numbers User Guide for iPhone, "Export to other file formats in Numbers on iPhone": the CSV option writes cell contents as values separated by commas; the TSV option separates them with tab stops. Retrieved 2026-10-30.
• RFC 4180, Common Format and MIME Type for CSV Files, section 2 (records on separate lines separated by CRLF, comma-separated fields, quoting rules) and section 3 (registration of text/csv with optional charset and headerparameters, "Common usage of CSV is US-ASCII"). Retrieved 2026-10-30.