How to Make a Practice Quiz from Photos, Scans and Slides

A lot of course material is not a tidy PDF full of selectable text. It is a phone photo of a whiteboard, a scanned handout from the library copier, or a lecture deck where half the slides are screenshots. All of these can become a practice quiz, but each one is read differently, and each one fails differently. This guide explains what happens to each kind of file, the limits worth knowing before you upload, and what to do when a file comes back with no text.

Disclosure: QuizForge is our product. Everything below describes how QuizForge handles uploads as of October 2026. Other tools work differently, but the advice on photos and scans applies to any of them.

The short version

• ✦Check the text box after uploading. Whatever was read from your file appears there. If it looks wrong, the quiz will be too.
• ✦One page per photo, flat, in good light, filling the frame.
• ✦PDFs: the first 60 pages are read, or the first 20 of a scan. Cut a long document down to the chapter you need, or split a long scan into 20-page files and upload them together.
• ✦Slides: text and speaker notes are read, text inside pictures is not. Export a picture-heavy deck as PDF instead.
• ✦One chapter per quiz beats a whole textbook. About 15,000 characters of your material go into each quiz.

What gets read, and how

Every file can be up to 20 MB, and you can upload several at once. Their text is added to the same box.

For text files, Word, PowerPoint and PDFs with real text, the reading happens in your browser and only the text is sent when you generate the quiz. Photos and scanned pages have to be sent as images so they can be read.

The habit that prevents most bad quizzes

After an upload, the text that was read appears in the box on the create page, with a character count under it. Spend twenty seconds looking at it before you press Generate.

You are checking for three things:

• ✦Is it your material? A scan that read as the cover page and a table of contents will produce questions about the cover page and the table of contents.
• ✦Is it complete? If a photo of a dense page came back as three lines, the photo was not sharp enough.
• ✦Is there junk? Running headers, page numbers, reference lists and copyright notices can be deleted right there.

You can edit the box freely, so fixing a garbled line or deleting a bibliography takes seconds. Generating needs at least 100 characters, and 500 or more gives the generator enough to work with.

Photos of notes, whiteboards and book pages

Phone photos are read by an AI vision model. Printed text in a clear photo usually comes through well, so most failures are photo problems, not reading problems.

• ✦One page per photo. Every photo is scaled down so its longest side is at most 2,000 pixels before it is sent. A two-page spread shot from a distance loses fine print in that step; a single page filling the frame does not.
• ✦Flat and square-on. Curved pages near a book's spine and steep angles distort the lines.
• ✦Even light, no glare. Glossy handouts under a ceiling light often have a white patch exactly where the important paragraph is.
• ✦iPhone photos (HEIC). Every photo is converted to JPEG in your browser before it is sent, which works for HEIC in browsers that can open it, such as Safari. A browser that cannot open it shows a notice instead; share the photo as JPEG from the Photos app, or take a screenshot of it, and upload that.

Charts, diagrams and figures in a photo are described along with the text. A photo with nothing to read at all, such as a blank page or a snapshot with no words in it, comes back as "No readable text was found" rather than as a description of the picture.

Scanned PDFs

A PDF is treated as a scan when it has almost no selectable text (under about 500 characters). The quick test is to try highlighting a sentence in your PDF viewer: if you cannot select individual words, it is a scan.

For a scan, the first 20 pages are turned into images and read by AI vision, in batches of five pages that run side by side. A full 20-page scan took about half a minute in our test. Prepare one like this:

• ✦Split long scans into files of 20 pages or fewer and upload them together. Each file is read on its own, so a 50-page chapter split into three files is read in full.
• ✦Remove cover, blank and contents pages first. They use up pages of the 20 and add nothing. A scan whose first pages are all blank or pictures can come back as unreadable.
• ✦Rescan rather than fight a bad scan. A blurred, skewed or faint scan reads poorly, and every question built on it inherits the errors.

Two other PDF problems have simple fixes. A password-protected PDF cannot be opened; printing it to a new PDF from your viewer removes the password. A PDF that will not open at all is usually a renamed or half-downloaded file; export it again from the original document.

Lecture slides

From a .pptx file, QuizForge reads the text on each slide and the speaker notes underneath. The notes matter more than people expect: in many decks, the slide is a picture and the actual explanation is in the notes.

Text inside pictures is not read from a .pptx. If your deck is mostly screenshots, scanned diagrams or images of text, export it as a PDF and upload that instead. When the exported PDF has almost no selectable text, it is read as a scan, picture by picture, and diagrams and charts are described along with the text. The 20-page limit for scans applies, so split a long deck into several PDFs.

If the deck has plenty of real text overall, the exported PDF is read as text and the pictures are skipped. In that case, add the key points from the picture slides to the speaker notes, or paste them into the box.

Older formats need converting first: save a .ppt as .pptx (and a .doc as .docx) from PowerPoint or Word, and export Keynote or Pages files as PDF.

Long documents: give it less

About 15,000 characters of your material go into each quiz, roughly five pages of dense text. When you upload more than that, QuizForge picks passages spread across the document, preferring the ones most central to the subject. If you fill in the optional Topic Focus field, it prefers the passages most relevant to that topic instead. If that selection step cannot run, it falls back to the first 15,000 characters.

So a quiz from a whole textbook is a quiz from a small sample of it. You get better questions from one chapter or one lecture at a time, and a series of chapter quizzes covers more ground than one big one.

When an upload comes back empty

If a file cannot be used, a notice names the file, says why, and tells you what to do. The box is always there for pasting text as a fallback.

Before you study from it

A quiz built from a photo is only as accurate as what was read from the photo. Once the quiz is generated, read the explanations for a few questions and check them against your notes, the same way you would check any AI-written quiz. There is a short routine for that in how to check an AI-generated quiz, and more on studying with practice tests in the student guide to lecture slides.

If you want to try it on your own notes, QuizForge's free plan gives you 2 quizzes a month with no credit card.