A good file name answers the question you will type into search six months from now. “scan0042.pdf” answers nothing. “2026-10-21 home insurance renewal.pdf” answers when, what and why.
Name files in this order: date (if it matters), subject, then version (only if there are drafts). Use the same order for every file of the same kind. A name should make sense to someone else without a code sheet.
Free tool: the file naming generator builds names in these patterns for you, with the date format, separator and version numbers kept consistent.
Patterns you can copy
| Use | Pattern | Example |
|---|---|---|
| Dated record | date subject | 2026-10-21 home insurance renewal.pdf |
| Monthly or yearly report | period subject | 2026-10 sales report.xlsx |
| Project draft | project subject version | garden plan v03.pdf |
| Lasting reference | subject only | washing machine manual.pdf |
| Receipt | purchase date shop item | 2026-09-14 best buy printer.pdf |
| Scanned letter | date sender subject | 2026-08-02 council tax bill.pdf |
These are examples, not rules. The point is that files of the same kind share an order.
Why year-month-day
Dates written as 2026-10-21 sort correctly by name on every computer. Dates written as 21-10-2026 or Oct 21 sort by day number or alphabetically, which mixes up years.
Use the date that matters for the record. For a receipt, that is the purchase date, not the day you downloaded it.
Keep the rules short
- Use words you would actually search for.
- Pick one separator and stick with it: spaces, hyphens or underscores. Spaces work fine on Mac, Windows and most cloud services.
- Use
v01,v02for real drafts. Avoid “final”, “final2” and “final-final”. - Keep names under about 60 characters so they show in full in most windows.
- Keep the file extension. Renaming
photo.jpgtophoto.pdfdoes not convert it.
Characters to avoid
Windows does not allow these in file names: \ / : * ? " < > |. Mac Finder does not allow a colon. If files move between Mac, Windows and cloud services, avoid all of them, plus a full stop at the end of a name.
Very long folder paths can also cause problems on Windows and in some sync tools. Keeping folders shallow helps.
Rename a batch
On a Mac:
- Select the files in Finder.
- Control-click and choose Rename.
- Choose Format to set a name plus a number, or Replace Text to change one word in every name.
- Check the example, then click Rename.
On Windows:
- Select the files in File Explorer.
- Press F2, type a name, and press Enter. Windows adds (1), (2), (3) to each file.
- For more control, Microsoft’s free PowerToys includes PowerRename, which can find and replace text across many names at once.
Try any batch rename on a few copies first. Open the results, then search for one by a word you would remember.
Renaming can break links
Spreadsheets, design files, video projects and websites often point to other files by name. Rename those files and the link breaks, even though the file itself is fine. Rename inside the app that uses them, or keep the old names for linked assets.
What to leave alone
- App files and anything inside an app’s folder
- Photo libraries managed by Photos, Lightroom or similar apps
- Paired files such as a photo and its sidecar file, or a video and its subtitles
Names alone do not prove two files are duplicates. Open both before deleting one.
Use folders for the bigger picture
A file name cannot carry every category. Use the folder system guide for Active, Reference and Archive, and the Downloads cleanup to name new files as you file them. On a Mac, tags add a second label without changing the name: see the Mac guide.
Rename steps checked against Apple and Microsoft help pages in November 2026.
Sources
- Microsoft Learn: Naming files, paths and namespaces
- Microsoft Learn: PowerToys PowerRename
