Compress Images for Google Forms, Moodle and LMS Uploads Without Ruining Text

You take a screenshot of a quiz question, a diagram, or a page of handwritten notes and upload it to your LMS, only to find the image is either rejected for being too large or so blurry after compression that the text is unreadable. This is one of the most common problems students and educators face when working with learning management systems, and it happens because screenshots and diagrams behave very differently from photos when you compress them.

This guide covers the exact settings to use for Google Forms, Moodle, Canvas, Blackboard, and Microsoft Teams so your images pass upload limits while staying fully readable.

Why LMS image uploads are more demanding than regular file sharing

Learning management systems often enforce tighter limits than email or cloud storage because they store files for every student in a course and disk space across an institution adds up quickly. An administrator who sets a 2MB per file limit in Moodle is not being unreasonable. They are managing storage for potentially thousands of concurrent uploads across every class in the system.

The challenge is that screenshots and document images are much harder to compress cleanly than photographs. A photo of a landscape compresses well because colour variation naturally absorbs JPEG compression artefacts. A screenshot with black text on a white background is unforgiving and any compression artefact shows up immediately as blurry edges around letters and numbers.

Upload limits by platform

These are the typical limits you will encounter, though individual institutions configure their own settings so you should always check your specific system.

Google Forms: 10MB per image upload. Google Drive attached files can be larger, but directly embedded images in forms are capped at 10MB.
Moodle: The default maximum is 2MB per file, though some institutions raise this to 5MB or 10MB. If your upload keeps failing with no clear size limit stated, assume 2MB is the target.
Canvas (Instructure): Typically 500MB per course file, but individual assignment submission limits are often set much lower by instructors, commonly 5MB to 25MB per file.
Blackboard: 250MB per course content item by default, with instructor-configured limits often lower for assignments.
Microsoft Teams (education): SharePoint limits apply, generally 250MB per file, but Teams assignment submissions are often limited to 100MB by administrators.
Google Classroom: 10MB per file for Drive-attached items when not using Drive for storage. If using Drive, files can be much larger but slow to load.

The right format for each image type

This is the most important decision and the one most people get wrong. Using the wrong format before compressing is why so many compressed images end up blurry.

Screenshots and screen recordings: Always use PNG. Screenshots contain text with sharp edges, and JPEG compression introduces blurring around those edges that makes text hard to read. A PNG screenshot may be larger than a JPEG but it stays sharp at any zoom level. The exception is screenshots with lots of photographic content like a screenshot of a video frame, where JPEG is acceptable.

Diagrams, charts, and flowcharts: PNG for anything with text labels, sharp lines, or solid colour regions. JPEG for anything that looks more like a rendered illustration with soft colour gradients. When in doubt, use PNG and reduce the resolution rather than switching to JPEG.

Scanned handwritten notes: JPEG works well here because handwriting has softer edges than printed text, and the paper texture provides enough colour variation that JPEG compression artefacts are less visible. Scan in grayscale rather than colour to cut file size significantly with no visible quality difference for most handwritten content.

Photographs embedded in documents: JPEG at 80 to 85 percent quality. There is no reason to use PNG for a photograph unless it requires transparency.

Graphs with fine detail: PNG unless the file size is too large after resizing. If you must use JPEG for a graph, keep quality above 85 percent to preserve axis labels and data point markers.

Resolution guide for LMS display

Most LMS platforms display images at screen resolution. A Moodle course page typically renders content in a column that is 700 to 900 pixels wide. An image that is 3000 pixels wide is being scaled down to fit, and all those extra pixels are adding file size with no visible benefit to the student viewing it.

For most LMS uploads, a width of 1200 pixels is more than enough for any image that will be viewed on screen. For images that students might download and zoom into, such as detailed diagrams or annotated screenshots, 1600 to 2000 pixels wide is a generous target that keeps detail while staying manageable in size.

Use the Image tools to resize to the appropriate width before compressing. Resize first, then compress. Doing it in this order gives much better results than compressing a large image and hoping the result is small enough.

Compressing screenshots without blurring text

This is the specific problem that catches most people out. Here is how to handle it properly.

If you are working with a PNG screenshot that is too large, the answer is almost never to convert it to JPEG. Instead, reduce the pixel dimensions. A screenshot that was taken on a 4K monitor at 3840 pixels wide can be scaled to 1400 pixels wide and will still be perfectly readable on any screen, while being roughly 8 times smaller in file size.

If after resizing the PNG is still too large and you genuinely need to switch to JPEG, use a quality setting of 90 percent or above. Below that threshold, you will start to see blurring around text edges. Check the result by zooming to 100 percent in your browser and reading the smallest text in the image. If it looks slightly fuzzy, increase the quality setting or go back to PNG.

Use the Image Cropper before resizing to remove any unnecessary whitespace or UI elements around the content. Cropping out a large empty margin can reduce file size significantly without affecting the content at all.

Scanned notes and handouts

If you are scanning physical notes, handouts, or worksheets to upload to an LMS, the scan settings make a bigger difference to file size than any compression you apply afterwards.

For typed or printed text, scan at 150 DPI in grayscale. This produces clean, readable text at a fraction of the size of a 300 DPI colour scan. If the document has images or diagrams, 200 DPI in grayscale is a safe target.

For handwritten notes, 150 DPI in grayscale is usually sufficient. Handwriting does not benefit from high resolution the way small printed text does, and the file size savings from keeping DPI low are significant.

If you are scanning multiple pages, convert the collection to a PDF using JPG to PDF rather than uploading individual image files. A single PDF is easier for students to navigate and often smaller than the equivalent set of individual JPEG or PNG files.

Privacy considerations for uploaded images

Images taken with a smartphone or digital camera embed EXIF metadata that can include the GPS location where the photo was taken, the device model, and timestamp information. If you are uploading images that contain any personal or sensitive content, remove this metadata before uploading.

Screenshots taken on a computer do not embed GPS data, but screenshots of browser windows can accidentally include account information, notification previews, or other personal details visible in the screenshot. Crop these out using the Image Cropper before uploading.

Practical workflow for LMS image uploads

Decide on format first. Screenshot or diagram with text means PNG. Photograph or scanned handwriting means JPEG. Grayscale scan of printed text also means JPEG.
Crop out unnecessary content using the Image Cropper. Remove borders, margins, and any personal information visible in the image.
Resize to the target width using the Image tools. For most LMS content, 1200 to 1600 pixels wide is appropriate.
Compress once using moderate settings. For PNG, a lossless compression pass is safe. For JPEG, use 80 to 85 percent quality for photos and 90 percent or above for anything with text.
Preview at 100 percent zoom and read the smallest text in the image. If it is clear, the file is ready to upload.
Check the file size against the platform limit before uploading. Use the Upload Limit Checker if you are unsure of the exact limit.

Common mistakes

Converting screenshots to JPEG to reduce size. This almost always produces blurry text. Resize the PNG instead.
Compressing without resizing first. A 4000-pixel-wide image compressed to 500KB still loads slowly and adds no quality benefit over a 1400-pixel version at the same file size.
Scanning in colour when grayscale is fine. A colour scan of a black and white handout is three times larger than the grayscale equivalent with no useful difference in readability.
Not cropping before resizing. Every pixel of unnecessary margin is wasted file size. Crop first, then resize.
Uploading individual scanned pages instead of a single PDF. Multiple files are harder to navigate and often larger in total than a properly assembled PDF.
Not checking at 100 percent zoom before submitting. An image that looks fine at 50 percent on your screen can have unreadable text when a student opens it at full size.

Frequently asked questions

Why does my screenshot look blurry after I compress it?

JPEG compression blurs sharp edges, which is what text consists of. Use PNG for screenshots, or if you must use JPEG, keep quality at 90 percent or above and check text readability at 100 percent zoom before uploading.

What is the difference between DPI and image quality?

DPI refers to the resolution of the original scan or capture, which determines how many pixels are in the image. Quality is the compression strength applied when saving. A 300 DPI scan saved at low JPEG quality will look worse than a 150 DPI scan saved at high quality, because the compression artefacts from low quality are more damaging to readability than reduced DPI. For LMS uploads, 150 DPI at moderate quality is a better target than 300 DPI at aggressive compression.

My Moodle upload keeps failing even though the image is under 2MB. What is wrong?

Check the allowed file types in the assignment settings. Some Moodle configurations restrict uploads to specific formats. If you are uploading a PNG and only JPEG is allowed, the upload will fail regardless of size. Also check whether the course has a maximum resolution setting separate from the file size limit.

Should I upload images directly or convert them to PDF first?

For a single image, uploading directly is fine. For multiple related images like several pages of scanned notes, converting to a PDF first with JPG to PDF is better because it creates a single navigable file and is usually smaller in total size than the individual images.

Is it safe to upload images containing personal information to an LMS?

LMS platforms are generally managed by your institution and have their own data policies. For images that contain sensitive personal information beyond what is relevant to the assignment, remove that content using the Image Cropper before uploading.

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Final takeaway

The most important rule for LMS image uploads is to choose the right format before doing anything else. PNG for screenshots and diagrams with text, JPEG for photographs and scanned handwriting. Then crop, resize to a sensible width, and do a single compression pass. Check at 100 percent zoom before uploading. Following that order produces readable images that pass upload limits every time. Start with the Image tools for cropping, resizing, and compression, and use JPG to PDF when you have multiple scanned pages to combine.