How this file size checker works
The browser reads the size recorded for each selected file and displays it in three units. For supported images, it also reads pixel width and height. The file contents never leave your browser.
Check any file size in bytes, KB and MB
Select one or more files to see their exact size, type, image dimensions and combined total. Nothing is uploaded.
ExactSizer calculates KB using 1 KB = 1,024 bytes and MB using 1 MB = 1,024 KB, the same units used by its exact-size compressor.
Your files stay on this device and are never uploaded.
Check against an upload limit
Enter the maximum size allowed by a form, email service or upload portal. Every selected file is marked as within the limit or too large.
Files checked: 0
Combined size: 0 bytes · 0 KB · 0 MB
No files selected
Choose files above to display their exact size.
Bytes, KB and MB converter
Convert a stated upload limit before compressing. This calculator uses binary file-size units: 1 KB = 1,024 bytes.
bytes1,048,576
KB1,024
MB1
File size conversion formulas
- Bytes to KB: divide the byte count by 1,024.
- KB to MB: divide the KB value by 1,024.
- MB to KB: multiply the MB value by 1,024.
When an exact file-size check helps
Upload limits
Confirm whether a document is below a portal's stated KB or MB limit before submitting it.
Batch totals
Add several attachments and check their combined size before sending an email or upload.
Image requirements
See both image dimensions and file size when a form specifies pixels as well as KB.
Is the file over the limit?
Open the exact-size compressor, enter the required KB or MB value and reduce the file locally.
File size checker questions
How can I check a file size online?
Choose the file in the checker above. Its exact byte count and converted KB and MB values appear immediately without an upload.
Is 1 MB equal to 1,000 KB or 1,024 KB?
This tool uses 1 MB = 1,024 KB and 1 KB = 1,024 bytes so its results match ExactSizer compression targets. Some storage vendors use decimal units, where 1 MB equals 1,000 KB.
Does checking a file upload it?
No. The browser reads local file metadata. ExactSizer does not send the selected file to a server.
Can I check several files at once?
Yes. Each file receives its own result, and the checker also calculates the combined size of all selected files.