Does changing the extension convert the file to that format?

No — this only changes the file's label, not its actual content or encoding. For real format conversion, use a dedicated converter for that file type.

When would I actually need this instead of a converter?

When a file's content is already in the right format but was saved or downloaded with the wrong extension — correcting the label fixes which app opens it by default.

Can I batch-change extensions on multiple files?

This tool focuses on one file at a time — for renaming many files at once, see the Batch File Renamer.

Does File Extension Changer upload my files to a server?

No. File Extension Changer runs entirely in your browser using on-device processing, your files never leave your device.

File Extension Changer

Rename a file's extension without converting its actual format.

Runs in your browser

Drop a file to change its extension

Choose File

About this tool

Changing a file's extension by renaming it doesn't convert the file — the underlying bytes stay exactly the same, only the label changes, which is fine when the extension was simply wrong but won't fix a file that's genuinely the wrong format. This tool renames a file's extension quickly without touching its actual content, useful for correcting a mislabeled file or matching what a particular piece of software expects to see, while making clear that this isn't a format conversion.

Frequently asked questions

Batch File Renamer

Rename many files at once using a pattern, and download them as a ZIP.

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Detect a file's true type from its byte signature, not just its extension.

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