excel file merge online free
You have several Excel or CSV files open and need to combine them quickly. DataMimi lets you merge these files online free without signing up or losing data formatting.
Merge multiple Excel or CSV files online free while preserving original formatting and without signing up.
Drop your file in and ask a question — no account needed.
Upload your spreadsheet.xlsx .xls .csv — free to try, no accountOr start with
What this export contains
| Sheet1 |
| Column1 |
| Column2 |
| Date |
| Amount |
| Description |
| ID |
| Status |
| Category |
| Total |
What usually goes wrong with it
Different column headers across files
Files often use slightly different column names or orders, making simple merges misalign data.
DataMimi DataMimi matches columns by header names even if they differ slightly across files.
Merged cells and multi-row headers
Excel exports sometimes have merged title rows or headers not on the first row, confusing automated merges.
DataMimi It detects merged cells and multi-row headers, letting you adjust before merging.
Data types changing after merge
Numbers stored as text or dates can convert incorrectly when files are combined, losing original formatting.
DataMimi DataMimi maintains original data types like dates and numbers stored as text during the merge.
Large files requiring upload without account
Many online tools limit file size or force account creation, complicating quick merges.
DataMimi Files upload from the browser with no account needed; the free plan takes files up to 25 MB.
Subtotal or total rows duplicated
Files with subtotal rows can cause double counting if merged without cleaning.
DataMimi Subtotal rows are detected and can be removed to avoid duplication in the merged output.
Common questions
What file types can I merge with DataMimi?
You can merge Excel files (.xlsx, .xls) and CSV files online.
Do I need to sign up to merge Excel files online for free?
No registration or account is required to merge files using DataMimi online.
How does DataMimi preserve original data formats during merge?
DataMimi detects and keeps number, date, and text formats as they appear in each file.
Can I merge files with different column orders or headers?
Yes, DataMimi aligns columns by header names and lets you preview before merging.
Are subtotal or total rows handled automatically?
DataMimi identifies subtotal rows and offers options to exclude them before merging.
Try it with your own file
DataMimi reads the file you actually have — merged cells, headers below row one, totals pasted at the bottom — and shows which rows and columns every number came from.
Ask about your file