--- title: "CSV splitter" description: "Split a large CSV file into smaller files by number of rows, or into a set number of files, with the header row on every file. Free, in your browser." canonical: https://www.acquisity.ai/tools/csv-splitter --- # CSV splitter > Split a large CSV file into smaller files by number of rows, or into a set number of files, with the header row on every file. Free, in your browser. Choose a CSV file and how to split it. With First row is a header on, every part repeats the header row, and you can download each part or all of them in one zip file. It runs in your browser, so your file never leaves your computer. Use the tool in a browser at [/tools/csv-splitter](https://www.acquisity.ai/tools/csv-splitter). It is free and needs no sign-up. ## How the file is split - Choose how many rows go in each file, 1,000 to start with, and every part gets that many rows except the last, which gets the rest. Or choose a set number of files, and the rows are spread over them as evenly as they go: 10 rows over 4 files makes files of 3, 3, 2 and 2 rows. - Rows keep their order, and every row is in exactly one part. With First row is a header on, as it is at the start, the first row that isn’t blank is the header row, and it’s copied into every part exactly as it is in your file, with any sep= line and any blank rows above it kept above it. - Each part is named after your file and keeps its .csv, .tsv or .txt ending, so leads.csv gives leads-part-1-of-3.csv, leads-part-2-of-3.csv and leads-part-3-of-3.csv, and contacts.tsv gives contacts-part-1-of-3.tsv and so on. Download each part on its own, or every part at once in one zip file. - Rows are copied as they are, not rewritten: the same commas, semicolons or tabs between cells, the same quotes and the same line endings as your file. Cells in quotes keep their line breaks, so a note that runs over several lines stays in one row, in a file with commas, semicolons or tabs between its cells, or one that starts with an Excel sep= line naming its separator. In a file that uses another separator, like | or ^, and has no sep= line, such a note can be split between rows, and so between parts, though every character is kept; starting the file with a line like sep=| keeps it in one row. Files saved as UTF-8 and files saved in Excel’s older Windows format are both read. Blank rows stay in the parts just as they are in your file, and each one counts as a row, wherever it is, except that with First row is a header on, blank rows above the header row go at the top of every part with it. So a part can hold only blank rows, such as the last part when your file ends with blank rows. - A file in valid UTF-8, or in UTF-16 that starts with its byte order mark, as Excel’s Unicode Text does, gives parts in UTF-8, each marked so that Excel shows accented letters as they are. A UTF-16 file without that mark isn’t read as text. Any other file, such as one saved in Excel’s older Windows format in any language, or a UTF-8 file with even one byte that isn’t valid UTF-8, gives parts with your file’s own bytes, in its own format, starting with your file’s mark if it has one, so a spreadsheet reads them as it reads your file. When your file starts with an Excel sep= line, that line is repeated at the top of every part, and no part carries a mark, whatever the file’s format, because Excel doesn’t read a sep= line that comes after one. - It makes at most 200 files at a time. If your settings would make more, it says so and how many rows in each file would fit. ## Putting files back together To combine the parts again, or lists from different places, use the [CSV merger](https://www.acquisity.ai/tools/merge-csv-files). It lines up columns by their header names and can drop rows that repeat an email address. ## What it doesn’t do It doesn’t split by the values in a column, and it doesn’t read Excel files (.xlsx), so save the sheet as CSV first. Your file is read in your browser and isn’t uploaded or saved. ## Questions ### How do I split a large CSV file into smaller files? Choose the file, then choose how many rows go in each file or how many files you want. It splits at once, and you can download each part or one zip file with every part. ### Does each file keep the header row? Yes, while First row is a header is on, which it is at the start. For a file with no header row, untick it and every row is split as data. ### How do I split a CSV file into equal parts? Choose a set number of files. The rows are spread as evenly as they go, so no two parts differ by more than one row. ### Can I split a CSV file that’s too big for Excel? Yes, up to 100 MB, which holds about a million rows of a lead list with a handful of columns. Past that, we split the first 100 MB, up to the last whole row, and say so. ### Can I split a CSV file by the values in a column? No. It splits by rows only, and keeps them in order. ### How many files can it make? Up to 200 at a time. If your settings would make more, it tells you the fewest rows in each file that fit. ### Is my file uploaded or stored? No. Your file is read and split in your browser, and it’s never sent to us or saved. ## Splitting a big lead list? On paid plans, when you upload leads to a campaign, Acquisity skips repeats, invalid addresses, people on your blocklist and people already in another campaign you haven’t archived, and shows you what it skipped. [Cold Email Agent](https://www.acquisity.ai/agents/cold-email). --- Web page: https://www.acquisity.ai/tools/csv-splitter Site index for agents: https://www.acquisity.ai/llms.txt