Fill Blank Cells in a CSV
Exports from spreadsheets often show a group name once and leave the cells below it empty. Fill them down, up or with a value, or fill missing numbers with the average.
Drag a file here or choose one
Worked examples
Fill down
Region,Rep North,Ann ,Bob South,Cara
Region,Rep North,Ann North,Bob South,Cara
Bob's blank takes the value above it.
Fill with the mean
Sales 10 (blank) 40
10 25 40
The mean of 10 and 40 is 25.
About Fill Blank Cells in a CSV
Reports with merged cells export a group name once and leave the cells beneath it empty. Surveys leave gaps, and exports use blanks for missing values. Filling down copies the value above into each blank until the next value appears, so every row carries its group. Filling up works from the other end, for tables where the label comes last. You can also fill with a value you type, such as 0 or Unknown.
For columns of numbers, fill with the mean, which is the total divided by the count, or the median, which is the middle value and is less affected by a few huge figures. The most common value suits categories. Choose the columns to fill, and tick the option to also treat N/A, NULL, none and a dash as blank. Blanks at the top of a column cannot be filled downwards, and the tool counts them for you. A table shows what was filled in each column.
How to use Fill Blank Cells in a CSV
- Paste your CSV or open a file.
- Tick the columns that need filling.
- Choose how to fill: the value above, the value below, a value you type, the mean, the median or the most common value.
- Check the counts and download the result.
Common uses
- Filling in group names left blank by merged cells
- Replacing missing numbers with the average before analysis
- Setting a default such as 0 or Unknown for empty cells
- Turning placeholders such as N/A into real values
Frequently asked questions
What is the difference between mean and median?
The mean is the total divided by the number of values. The median is the middle value when they are in order. One very large value pulls the mean up but barely moves the median.
Why are some blank cells left?
Cells at the start of a column cannot be filled from above, and cells at the end cannot be filled from below. They are counted as left blank so you can decide what to do.
What counts as blank?
A cell that is empty or holds only spaces. Tick the option to also treat N/A, NULL, none, NaN and a dash as blank.
Does filling change cells that already have values?
No. Only blank cells are filled.
What if a column has no numbers?
The mean and median need numbers, so a column without any is skipped and reported. Choose the most common value or a value you type instead.