Put two texts or files side by side and see what differs, line by line and character by character. Copy changes across or edit either side, then save a copy. Drop a folder or ZIP on each side to compare their contents at once.
Your files are never sent to a server (processed in your browser)
Folders can’t be chosen on phones, so choose a ZIP instead.
Check files or folders to save only those as a ZIP. Use “→” and “←” to copy files to the other side, or “✕” to remove a file that exists on only one side. Edits made in the compare view are applied to that file too. Copies, removals and edits happen only in your browser, and your original folders and ZIPs stay unchanged. Use “Save as ZIP” to keep the result.
| Name | Left | Status | Right |
|---|
Only on the left (removed) Only on the right (added or changed). In the single column view, you edit the right side.
Drop a folder or ZIP on each side (or use “Choose folder” / “Choose file”) to compare the contents of two folders or ZIPs at once: folder to folder, ZIP to ZIP, or a folder to a ZIP. Files at the same path are compared and sorted into four groups:
Contents are compared by size and by a checksum (CRC32) of the data. For ZIPs the checksum stored in the archive is used, so nothing needs to be extracted. Results appear as a folder tree, and selecting a file shows exactly what changed in the compare view right below.
Use “→” and “←” in the tree to copy a file or folder to the other side, and “✕” to remove a file or folder that exists on only one side. Edits you make in the compare view are applied to that file too. Copies, removals and edits happen only in your browser, and your original folders and ZIPs stay unchanged. Use “↺” to undo them.
Save the result with “Save as ZIP”. You can choose changed and one-side-only files (handy for handing over just the updates), all files (the finished version with your copies and edits), or only the files you copied or edited. The list of results can also be saved as CSV.
This tool compares every character exactly, including spaces and line breaks. It also detects and reports the usual culprits when two texts look the same but don’t match:
If those are the only differences, the tool says so plainly. Turn on "Show whitespace & line breaks" to see them marked. "Identical" is shown only when the two sides match character for character.
When both sides are tabular data such as CSV or TSV, choose Table (CSV) under "Compare as". Cells are compared one by one, changed cells are highlighted, and the exact characters that changed are marked.
You can edit right in the table. Click a cell to select it, then click (or tap) it again to change it (Enter to confirm, Shift+Enter for a new line, Esc to cancel). Use "Copy right →" or "← Copy left" to copy the selected cell, or a row selected by clicking its number, to the other side. Rows that exist on only one side are added or removed as a whole. Undo with the ↶ ↷ buttons (Ctrl+Z / Ctrl+Y). Edits go straight into the underlying text and keep the original CSV formatting such as quoting, so you can save right away.
Choose Side by side under "Layout" to show the left and right tables next to each other; they always scroll together.
Both sides work like a regular text editor, and the differences update as you type. Undo with Ctrl+Z (⌘+Z on a Mac).
Copying always goes from the side you’ve selected to the other side. In the side-by-side layout, put the cursor on the left (or select a cell or row on the left in the table view) and the button becomes "Copy right →"; select the right side and it becomes "← Copy left". The arrow buttons between the two sides point the same way. In the single-column layout, both buttons are shown. In the text view, the buttons copy only the line with the cursor (or the differing lines you’ve selected), while the arrow buttons between the sides copy the whole block. Use ↶ ↷ to undo and redo.
Saving never touches your original file: a copy is downloaded with "_left" or "_right" added to the file name (for example, data_left.csv). The encoding, line endings and BOM of the loaded file are preselected, so CSVs still open correctly in Excel. If the text contains characters that can’t be saved in Shift_JIS (such as emoji), you’re told before anything is saved.