How to submit handwritten homework as one readable PDF from your phone

Plenty of courses still run on paper. You solve the problem set by hand, and then the learning platform (Google Classroom, Canvas, Moodle, a college portal) asks for "a single PDF". The same few problems tend to come up: pages out of order, sideways photos, pencil that vanished in compression, and a huge file that's slow to open on a laptop. Here's a short workflow that avoids all of them, using nothing but the phone you already have.

1. Write for the camera, not just the page

A few small choices make the photo far easier to read later:

• Use a dark pen or a soft pencil (2B or darker). Light HB pencil looks fine on paper and almost disappears once the file is compressed.
• Leave a margin. Writing right up to the edge means the edge is what gets cropped.
• Number every page at the top, like "Q3 – page 2 of 4". If anything ends up out of order, the reader can still follow it.
• Write your name on page one. File names get renamed by portals; the page doesn't.

2. Photograph each page the same way

Consistency matters more than an expensive camera.

• Put the sheet on a plain, darker surface so the page edge stands out.
• Stand so the light comes from the side. Overhead light puts your phone's shadow right across the middle of the page.
• Hold the phone flat and parallel to the paper. Tilted shots turn the page into a trapezoid, and the bottom lines get smaller and blurrier.
• Fill the frame with the page but keep all four corners visible.
• Skip the flash. On glossy worksheets it creates a white patch exactly where your working is.

Take a second shot of any page you're unsure about. Re-shooting now takes five seconds; re-shooting after the deadline isn't possible.

3. Check orientation before you convert

Phones store rotation as a flag in the photo's metadata, and not every app respects it. A page that looks upright in your gallery can come out sideways in a PDF. Open each photo once, and if it's rotated, use the gallery's rotate button and save. That bakes the rotation into the image itself.

4. Put the pages in order, then make one PDF

Most portals accept one file per assignment, so merge everything into a single document. I use JPG to PDF Mobile, a free converter that runs entirely in the browser: you add the photos, drag them into order, pick a page size and convert. Because the conversion happens on the device, the photos aren't uploaded anywhere, which is nice when a worksheet has your full name and student ID on it. Any converter that lets you reorder pages and choose quality will do; the important part is the order and the settings, not the tool.

Settings that work well for handwritten pages:

• Page size: A4 or Letter, whichever your school uses. "Fit to image" is fine too, but a fixed size prints more predictably if the teacher prints submissions.
• Quality: start at the balanced/medium setting. Handwriting is high-contrast, so it survives moderate compression much better than photos of people do.
• File size target: check the portal's upload limit first; it's usually shown next to the upload button, and some forms are as strict as 1–2 MB. If you're over, drop one quality step and convert again rather than deleting pages.

5. Open the PDF the way your teacher will

Before you upload, open the finished PDF on your phone and zoom in to 100% on the hardest page, usually the one with the smallest writing or the faintest pencil. Ask yourself:

1. Can I read every line without squinting?
2. Are the pages in the order I numbered them?
3. Is anything cut off at the edges?
4. Is the file under the portal's size limit?

If all four are yes, upload it. If not, fix the specific page and regenerate. It's much faster than redoing everything.

6. Name the file like a grown-up

Portals often keep your original file name, and teachers download dozens of them. Something like Surname_Firstname_Physics_HW3.pdf makes life easier for whoever grades it, and makes it easy for you to find again if there's a dispute about a missing submission.

A two-minute version

If you're in a hurry: dark pen, side light, phone flat, fix rotation, merge in order, medium quality, zoom-check the worst page, sensible file name. That's the whole routine, and it turns "the PDF won't open / page 3 is sideways" emails into a thing of the past.

If you have a trick for getting faint pencil to show up better in photos, I'd love to hear it in the comments.