What "Replace All" Does in Google Colab
Replace All in Google Colab finds every instance of a word or phrase in your notebook and swaps it for something else in one action. You open the Find and Replace dialog, type what you want to find and what you want to replace it with, then click Replace All — and every match changes at once. This saves you from clicking "replace" dozens of times if you've used the same variable name or function throughout your code.
The feature works on the text in code cells, markdown cells, and cell output. It does not search across multiple notebooks — only the one you have open right now.
Key Takeaways
- Open Find and Replace by pressing Ctrl+H (Windows) or Cmd+Option+F (Mac), or use the Edit menu.
- Type the text you want to find in the first field and the replacement text in the second field.
- Click Replace All to change every match in the notebook at once, or click Replace to change one at a time.
- Replace All works on code and markdown cells but cannot undo changes across the entire notebook if you make a mistake, so review the matches first.
- The search is case-sensitive by default, but you can toggle case-insensitive search using the Aa button.
Opening the Find and Replace Dialog
The fastest way to open Find and Replace is to use the keyboard shortcut. On Windows or Linux, press Ctrl+H. On Mac, press Cmd+Option+F. A panel will appear on the left side of your notebook with two text fields: one for what you're searching for and one for what you want to replace it with.
If you prefer the menu, click Edit in the top menu bar, then select Find and replace from the dropdown. This opens the same panel.
Typing Your Search and Replacement Text
In the first field (labeled "Find"), type the exact text you want to search for. This might be a variable name like old_data, a function name, or any string of characters. In the second field (labeled "Replace"), type what you want to replace it with — for example, new_data.
By default, the search is case-sensitive, meaning Data and data are treated as different. If you want to search without caring about uppercase or lowercase, click the Aa button (the case-sensitivity toggle) to turn it off. You'll see the button change appearance when it's active.
Some users also want to search for whole words only — so searching for "run" won't match "running". Look for a Match whole word option (usually shown as an icon with word boundaries) and toggle it if you need that precision.
Using Replace All vs. Replace One at a Time
Once you've entered your search and replacement text, you have two choices. The Replace All button (usually marked with a double-arrow or "Replace All" text) changes every match in the notebook when ready. The Replace button (or a single-arrow icon) changes only the next match, and you can click it repeatedly to go through matches one by one.
Replace All is faster when you're confident about the change — for instance, renaming a variable you created and used throughout your code. Replace one at a time is safer when you're unsure whether every match should change. For example, if you search for "data" and it appears in comments, variable names, and strings, you might want to skip some matches.
Colab will show you how many matches it found before you click Replace All, so you can see the scope of the change.
What Happens After You Replace
After you click Replace All, the changes take effect when ready in your notebook. The Find and Replace panel stays open so you can make another search if needed. Close it by pressing Escape or clicking the X button.
Unlike some text editors, Colab does not maintain a separate undo history for Replace All across the entire notebook — you can undo with Ctrl+Z (or Cmd+Z on Mac), but only the most recent action. If you've made other edits since the replacement, undoing may not work as expected. For this reason, it's wise to review the matches before clicking Replace All, especially if you're replacing something common.
Limitations and When to Be Careful
Replace All searches only the notebook you have open. If you need to change the same text across multiple notebooks, you'll have to open each one and run the replacement separately. There is no batch replace across files.
The search also matches text inside strings and comments, not just code. If you have a comment that says "the old_data variable" and you replace "old_data" with "new_data", the comment will change too. This is usually fine, but it's worth knowing.
Finally, if your notebook is very large or has many cells with output, the search may take a moment to complete. Colab will show a progress indicator while it works.
Frequently Asked Questions
Can I undo Replace All if I make a mistake?
Yes, press Ctrl+Z (or Cmd+Z on Mac) when ready after the replacement. However, if you've made other edits since then, the undo may not work as expected. For safety, review the number of matches before clicking Replace All.
Does Replace All work on output cells?
No. Replace All only changes the code and markdown you wrote, not the output that Colab generated when you ran the cells. If you need to change something in the output, you'll have to re-run the cells after fixing the code.
Can I search for special characters or line breaks?
You can search for most special characters by typing them directly. Searching for line breaks or regex patterns depends on whether Colab has a regex mode enabled — check the Find and Replace panel for a regex toggle (usually marked with .*). If it's not available, you may need to search for text patterns manually.
What if I only want to replace text in one cell?
Click inside the cell you want to edit, then use Find and Replace as normal. Colab will search the entire notebook, but you can use the Replace button (not Replace All) to skip matches in other cells and only replace the ones you want.
Does Replace All work in shared notebooks?
Yes, but if someone else is editing the notebook at the same time, their changes and yours may conflict. Colab will warn you if there's a conflict. It's safest to use Replace All when you're the only person actively editing.