Compare Files
Compare two versions of a file on a shared key column. Every row comes back labeled new, removed, changed or unchanged, and a column gap is noted once.
By Operelio team · Updated October 9, 2026
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What it does
Compares an original file with an updated version of it, using a shared key column. Every row is labeled as new (only in Updated), removed (only in Original), changed (in both but with different values), or unchanged.
Rows are matched by the key column, not by position, so the comparison stays correct even when rows are added, removed, or reordered between versions.
If one file has a column the other does not (a new export field, for example), that is reported once as a note. Its values come through, but they never count as changes, so a column difference cannot drown out the real value changes.
How to use it
Upload two files
The first is the original, the second is the updated version. Swap puts them the other way round.
Pick what to match rows on
Under Match rows on, pick the column in each file that identifies a row, like an ID or email. A column with the same name in both files is picked for you. Add another column to match on more than one.
Choose what counts as the same
Different case and spaces at the ends are ignored by default, so ABC and abc, or a value with a trailing space, are not changes. Uncheck either to count them.
Choose what goes in the file
Every row, labeled (the default), new rows only, changed rows only, removed rows only, or just the counts. All five are on every plan. The preview shows the file's own rows before you run.
Run the comparison
Click Compare files. Operelio writes an output file. Every mode but the counts ends with a Change type column showing each row's category; just the counts writes a small table of counts.
What goes in the file
| Mode | What it includes |
|---|---|
| Every row, labeled | All rows from both files, with a Change type column and a Changed columns column spelling out each edit (e.g. Plan: Free -> Starter). Unchanged rows are included by default; uncheck Include unchanged rows to leave them out. |
| New rows only | Just the rows that are in Updated but not Original. |
| Changed rows only | Just the rows that exist in both files but have different values, with a Changed columns column spelling out each edit. |
| Removed rows only | Just the rows that are in Original but not Updated. |
| Just the counts | One small table of counts, no rows: how many new, removed, changed and unchanged, and how many rows each file has. Downloads as CSV. |
Color-coded Excel output
When you download as .xlsx, the output is color-coded: green rows are new, red rows are removed, yellow rows are changed. Individual cells that changed within a row are highlighted in a darker yellow so you can spot exactly what is different.
What the results show
When the job finishes, its page shows:
New, Changed, Removed and Unchanged
How many rows are only in Updated (new), only in Original (removed), in both with a value that differs (changed), and the same in both (unchanged).
The settings
A line names the key columns, what the result holds, and whether case and spaces were ignored. A note says which columns have the most changes, like Most changes are in Plan (29) and Phone (10).
Your files
The Result, Original and Updated, each with its rows and the date it's kept until. Download any of them. On Starter and up, you can also send the result to Files.
Preview
Every row of the result, a page at a time. With every kind of change in one file, pick All, New, Changed, Removed or Unchanged to see just those rows. Search it, or go to a row, before you download.
Compare two versions of a file and see which rows are new, removed or changed.
Frequently asked questions
What if the two files have different columns?
Operelio starts with all columns from Original, then adds any columns that only Updated has. Their values come through but never count as changes, and a note under the settings names them. Missing values are left blank.
What plan do I need?
Every output mode, multi-column matching, and the color-coded Excel output are on every plan, including Free. What changes with the plan is how many rows and how large a file you can put through.
Ready to get started?
Upload a file and run your first transformation. Free, no credit card required.