9 patterns
Files & Paths Regex Patterns
File-related validation patterns for checking extensions, MIME types, file paths, and encoded content. Essential for file upload validation and file system operations.
Common Use Cases
All Files & Paths Patterns
File Extension
Extracts file extension.
\.([a-zA-Z0-9]+)$Image Files
Validates common image extensions.
\.(jpe?g|png|gif|bmp|svg|webp)$Video Files
Validates common video extensions.
\.(mp4|avi|mov|wmv|flv|webm|mkv)$Safe Filename
Validates filenames without special characters.
^[a-zA-Z0-9_-]+\.[a-zA-Z0-9]+$Data URI (Base64 Image)
Validates base64-encoded image data URIs
^data:image/(png|jpeg|gif|webp|svg\+xml);base64,[A-Za-z0-9+/]+=*$MIME Type
Validates standard MIME type strings (type/subtype format).
^(application|audio|font|image|message|model|multipart|text|video)\/[a-zA-Z0-9][a-zA-Z0-9!#$&\-^_.+]*$Unix / Linux Absolute Path
Validates absolute Unix/Linux file paths starting with /.
^(\/[^\/\0]+)+\/?$Windows Absolute File Path
Validates Windows absolute file paths (C:\folder\file.txt).
^[A-Za-z]:\\(?:[^\\/:*?"<>|\r\n]+\\)*[^\\/:*?"<>|\r\n]*$Windows Drive Letter Path
Matches an absolute Windows path starting with a drive letter (C:\, D:/foo, etc.).
^[A-Za-z]:[\\\/](?:[^<>:"|?*\r\n]+[\\\/]?)*$Frequently Asked Questions
How do I validate a file extension?
Use a pattern like ^.+\.(jpg|jpeg|png|gif|pdf)$ - adjust the extension list to your needs.
How do I validate a MIME type?
Use the MIME Type pattern which checks for valid type/subtype format.
How do I prevent path traversal in file paths?
Reject paths containing ../ or ..\ - regex: (\.\.\/|\.\.\\ ) - but also normalize paths server-side.
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