File Metadata Viewer Online — View File Properties
View file metadata online — name, size, type, last modified date and extension. Free, instant, browser-based.
File metadata is the information about a file rather than its content — the name, size, type (MIME), and last modification date. This tool reads these properties from the File API without reading the file contents, making it instant even for very large files. It is useful for quickly checking file details, verifying that a file has the expected MIME type, checking the file size before uploading, or confirming the last modified timestamp.
How to use
- Drag and drop any file onto the upload area, or click 'Choose File'.
- The file metadata is displayed instantly in a table — no button press required.
- View the file name, size (in bytes, KB, and MB), MIME type, extension, and last modified date.
FAQ
What metadata is displayed?
The tool displays: File Name (the full name including extension), File Size (in bytes, kilobytes, and megabytes), MIME Type (the file's type as reported by the browser, e.g. image/jpeg, application/pdf), File Extension (extracted from the filename), and Last Modified (the date and time the file was last changed on the filesystem, formatted in your local timezone).
Does the tool read the file contents?
No. All displayed information comes from the File object's metadata properties (file.name, file.size, file.type, file.lastModified), which the browser provides without reading the file's actual content. This makes the operation instant regardless of file size, and means no file data is ever processed or transmitted.
Why does the MIME type show as empty or generic?
The MIME type is determined by the browser based on the file extension. If the file has no extension, or if the browser does not recognise the extension, the MIME type may be an empty string or 'application/octet-stream' (the generic binary type). The browser does not read the file header (magic bytes) to determine the true MIME type — it relies on the filename extension only.
What does 'Last Modified' mean?
The Last Modified date is the date and time the file was last written to on the filesystem where it is currently stored. This is the same date you see in File Explorer (Windows) or Finder (Mac). Note that copying a file may or may not preserve the original modification date, depending on the operating system and copy method. Files downloaded from the internet typically have a modification date equal to the download time.
Can I view metadata for multiple files?
This tool displays metadata for one file at a time. After viewing a file's metadata, you can drop a new file to replace it. There is no batch mode for viewing metadata of many files simultaneously.
Is the file content read or uploaded?
No file content is read or uploaded. Only the metadata properties exposed by the browser's File API are accessed. The file bytes themselves are not read. This means the tool is safe for any file, including very large files, and no data leaves your device.