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File Submission Checker: Preflight Your Files Before Upload

Sending the wrong file is an avoidable mistake. This free file submission checker runs a preflight check on your files before you upload them to an employer, university, printer, client or government portal. Everything runs in your browser, so your files are never uploaded or stored.

Drop files here or click to choose.
PDF, images, Office files and ZIP archives. Nothing leaves your device.

What the file submission checker tests

  • File type and content: flags extensions that are not allowed and files whose real content does not match the extension, such as a renamed image saved as .pdf.
  • Size: checks each file and the combined total against your limit.
  • Filenames: catches illegal characters, spaces, double extensions, reserved names, non-ASCII characters and names that are too long.
  • Missing and duplicate documents: confirms each required document is present and finds duplicates by name and by identical content.
  • Image resolution: reads pixel width and height and compares them to your minimum.
  • PDF page dimensions: reads page count and page size, then checks it against A4, A3, A5 or Letter.
  • ZIP archives: lists contents, flags junk files like __MACOSX, and finds broken links to missing images, stylesheets and scripts inside HTML and CSS files.

How to check your files before uploading

  1. Pick the submission type that matches your workflow, or set your own limits.
  2. Check the required documents list and edit it if the portal asks for something different.
  3. Drop all the files you plan to send, including any ZIP.
  4. Fix every red item, review the orange warnings, then copy or download the report.

Why a preflight check saves you time

Portals often reject a submission after you click send, or worse, accept it and fail later at review. A single preflight report shows every problem at once, so you fix them in one pass instead of discovering them one rejected upload at a time.

Limits of the checker

Image resolution is measured in pixels, because pixel density (DPI) only has meaning at a physical print size. PDF page size is read from the file structure; PDFs that store their page tree in compressed form may show a warning instead of a size. Always confirm the final rules on the portal or in the instructions you were given.

What the file submission checker tests

No. All checks run locally in your browser. Your files never leave your device.

It depends on the portal. Many job and university systems limit files to between 1 MB and 10 MB each. Use the limit stated in the application instructions.

Avoid / \ : * ? ” < > | and control characters. Spaces and accented letters are legal, but some portals reject them, so underscores and plain letters are safest.

Add the PDF to the checker and choose the required size. It reports each page size in millimetres and flags files that do not match A4, A3, A5 or Letter.

Yes. For HTML and CSS files in a ZIP, it checks that every relative image, script, stylesheet and font reference points to a file inside the archive.

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