Uppercase Filenames
Uppercase Filenames calls toUpperCase() on every full selected filename, including the extension, and packages the resulting copies in renamed-files.zip. It provides no locale choice, transliteration, preview, link updating, or collision handling. Names that differ only by case can collapse, and expanding Unicode case mappings can change character count.
Runs locally — files stay on your deviceDoes uppercasing modify the original files?
No. It downloads copies inside a ZIP.
Unicode case mapping is not a reversible rename scheme
Uppercase conversion can map multiple source strings to the same result and can expand some characters, so converting back may not recover the original name.
How it works
Each File.name is transformed with JavaScript String.toUpperCase and used as the entry name in renamed-files.zip.
Key concepts
Extension included
report.pdf becomes REPORT.PDF.
Mappings may expand
Unicode uppercase is not always one input character to one output character.
When to use it
- Create uppercase copies for a defined naming convention.
- Normalize extensions for a legacy workflow.
- Prepare a small reviewed batch.
When not to use it
- Do not assume reversible conversion.
- Do not ignore files that differ only by case.
- Do not expect imports, URLs, or references to be updated.
Worked examples
Document
- Input
Q2-report.pdf- Expected output
Q2-REPORT.PDF
Digits and punctuation stay unchanged.
Already uppercase
- Input
README- Expected output
README
No visible change.
Case pair
- Input
data.csv and DATA.csv- Expected output
Duplicate-name risk
Both target the same casing.
Common mistakes
Expecting reversible names
Case mapping can lose distinctions. Correction: Keep an original mapping.
Breaking case-sensitive links
Dependent content is untouched. Correction: Update references explicitly.
Missing collisions
No uniqueness check runs. Correction: Audit target names first.
Best practices
- Review Unicode and collision-sensitive names.
- Maintain a rename mapping.
- Test the extracted result on the destination filesystem.
Related operations and differences
Add Prefix to Filenames
Choose Add Prefix to Filenames when you need to add a prefix to selected filenames.; use Uppercase Filenames specifically for rename upper.
Add Suffix to Filenames
Choose Add Suffix to Filenames when you need to add a suffix before every extension.; use Uppercase Filenames specifically for rename upper.
Lowercase Filenames
Choose Lowercase Filenames when you need to convert selected filenames to lowercase.; use Uppercase Filenames specifically for rename upper.
Replace Text in Filenames
Choose Replace Text in Filenames when you need to replace exact text across selected filenames.; use Uppercase Filenames specifically for rename upper.
Compare Two Files
Choose Compare Two Files when you need to compare two files securely by SHA-256.; use Uppercase Filenames specifically for rename upper.
File Checksum Comparator
Choose File Checksum Comparator when you need to compare a file digest with an expected checksum.; use Uppercase Filenames specifically for rename upper.
Limitations and privacy
- No locale choice, preview, mapping, collision handling, transliteration, path preservation, dependency updates, or in-place rename.
- The complete name including extension changes.
- Output is renamed-files.zip.
Processing happens in this browser. Selected file contents are not uploaded by this tool.
Downloads and copied results remain on this device; handle them according to their sensitivity.
Frequently asked questions
Is the extension uppercased?
Yes.
Is conversion reversible?
Not reliably for every Unicode name.
Are references updated?
No.
What is downloaded?
renamed-files.zip.