Table of Contents

Troubleshooting Submission Upload Issues


Submission best practices

When you start to work on any assignment that you'll be submitting to Gradescope, it's recommended that you leave yourself ample time to upload your files. If you are working on a variable-length or online assignment where your instructor has allowed you to choose the type of file you'd like to upload, it's highly recommended that you submit PDFs rather than images. If you will be scanning your work, it's also highly recommended that you use the scanning apps and instructions in the Scanning Work on a Mobile Device article to create PDFs that are small in size, high-resolution, and are guaranteed to work with Gradescope. If you've used the best practices explained above and are having issues submitting your work, see the table and steps below to try to fix the problem.

If all else fails, please contact from the email address associated with your Gradescope account. In your message, be sure to include the name of the course, assignment, and a screenshot or screen recording of any error notifications you see.

General troubleshooting steps

  1. Use the Possible problems and solutions table below to try to determine the cause of your submission errors. Correct the errors, if possible. Be mindful of how much time you have left before the due date will pass or the timer will run out (if your assignment has a time limit).
  2. Then, try to open the assignment in Gradescope.
    1. Assignment still opens: If you're prompted to submit your work, follow the instructions in the Submitting an Assignment guide. If you're trying to resubmit, check for a Resubmit button at the bottom of your screen. If you still see one, click the Resubmit button and re-upload your work. Unless you were working on an Online Assignment, be sure to wait for an emailed submission receipt and a success notification on your screen before navigating away.
    2. Assignment does not open / no Resubmit button: Your timer may have run out or your due date may have passed, so you will not be able to resubmit. If you suspect that's the case, then contact your instructor to see how they would like you to proceed. If needed, your instructor will be able to submit your work for you or extend your time limit at their discretion.

Possible problems and solutions

Incorrect file type

There are different types of assignments your instructor can create in Gradescope. For each assignment type, Gradescope will only accept certain file types. They are as follows:

  • Templated assignment (exams): single PDF only
  • Variable-length assignment (homework): single PDF or one or more images, which can be jpg/jpeg, png, gif, or heif/heic files
  • Bubble sheet assignment: single PDF of Gradescope's bubble sheet template only
  • Programming assignment: Any file type
  • Online assignment (file upload fields): Any file type

If you submitted one of the acceptable file types listed above, but you still can't upload your submission, double-check that your file-type extensions were written correctly. For example, make sure all jpegs have ".jpg" and all PDFs have ".pdf" at the end of the file names. Then, check for missing periods in your file extensions. Finally, make sure that the file extension listed for each file is the correct one. For example, check that files with ".pdf" extensions are not actually jpegs.

Tried to upload multiple PDFs

If you're submitting a PDF to a variable-length, templated, or bubble sheet assignment, you will only be able to submit a single PDF. Therefore, if you have multiple, separate PDFs to submit, you need to consolidate them into one PDF first. To protect your privacy, it is not recommended that you use free PDF-combining websites or apps to do that. Instead, if you're not sure how to combine multiple PDF files, try one of the solutions below.

  • For Mac users (Preview app): In the Preview app on your Mac, open the PDFs you want to combine. In each open PDF, choose View > Thumbnails. Decide which PDF will be your main PDF. Drag the appropriate page thumbnails from the other PDFs into the main PDF. To add an entire PDF, open Finder and drag the appropriate PDF icon to the sidebar of your main PDF.
  • For those with Adobe Acrobat: Open Acrobat DC. Click File > Create > Combine Multiple Files into a single PDF. If the file is already open, click Combine Files from the right menu. Click Add Files or Add Open Files, or drag files (including images, PowerPoints, etc.) into the Add Files window. Click Combine to merge all of the files into one PDF.
  • For handwritten assignments: If you're handwriting your assignment, see our Scanning Work on a Mobile Device guide for how to convert photos of your pages into a single PDF using a free scanning app.
  • With Gradescope staff assistance: If it's before the due date/time limit, you can also email your PDF files to and the Gradescope team will combine them for you. Please note that you will still need to submit the file.

Unstable internet connections

Sometimes spotty WiFi and unstable internet connections interrupt the submission process and your files do not upload to Gradescope. Double-check that your internet is working correctly.

Browser issues

If you see a "422 error" or if the Upload PDF or Upload image buttons on Gradescope are not clickable, you may be having problems with your internet browser. If you suspect this may be the problem, clear your browser cache or cookies, or try accessing the assignment on a different browser or device.

Image-related errors

It's highly recommended that you upload PDF files rather than images to Gradescope. However, if you do upload images and you're having issues submitted them, one of the following image-related errors might be the cause:

  • At least one question is missing an uploaded image
  • At least one uploaded image is too large (larger than 100MB)
  • At least one image has an incorrect file extension
  • At least one image was uploaded late after the due date/time limit expired (and therefore none of the images are submitted)

Please note that if you are planning to upload image files, leave yourself plenty of time before the due date passes or the time limit expires for your images to upload, especially if you're uploading images to multiple questions and/or your internet connection is slow or unstable.

Assignment time limit ran out

It's possible that your files did not upload because you were working on a timed assignment and your timer ran out. If you were in the process of uploading a submission file when the assignment time limit expired, then your file(s) would not have been accepted. You'll know the assignment you were working on had a time limit if you had to click a Start Assignment button to begin working and you saw a countdown clock in the top right of your screen after starting the assignment.

Navigating away before upload was completed

It's possible that your submission did not go through because you closed or navigated away from your Gradescope window before the upload was complete. Except in Online Assignments, you'll be able to tell that your upload was successful if you received an on-screen success notification and an emailed submission receipt from Gradescope.

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