Compress Video for Canvas, Moodle and Blackboard, and Shrink PDFs Too

It depends on the platform, and then on your school. We opened each page below on 9 October 2026 and took the figure from the page itself. Where a row names a school, that school is describing its own setup; the Canvas, Blackboard, Moodle, Microsoft and Google rows come from those organizations’ own documentation.

Three things to take from it. First, the number on your school’s form is the number that counts. Miami enforces 500 MB on Blackboard, while Reading, in its September 2024 post, caps Office files and images at 250 MB, audio at 25 MB and sends all video to YuJa. Second, a stated limit is a ceiling, not a promise: the college that quotes Canvas Studio’s 10 GB warns that uploads can fail well below it, mostly because of transfer time on a slow connection. Third, Canvas has more than one ceiling. Instructure lists 5 GB for ordinary files, 500 MB for audio and video through its media tool and 10 GB in Studio, so the same recording can fit one door and not another. Bowling Green keeps hosted media under 500 MB and points larger video to Studio.

Google Classroom is different. Its limits page lists class sizes, topics and invitations, and we found no per-file figure on it. Storage is what stops people. Google’s Workspace for Education storage overview says that when a teacher’s storage is full, students can’t submit assignments with file attachments. If a student sees “Couldn’t attach file”, Google’s troubleshooting page suggests attaching the video in Stream and pasting the link, or opening the Classwork folder, uploading the file to the Class Drive and sharing it with the class group.

To find your own limit, search your school’s IT knowledge base for the platform name plus “file upload limit”, as Miami and others publish one, or ask the help desk. Administrators can read it where it is set: in Moodle under Site administration > Security > Site security settings > Maximum uploaded file size (menu names can vary by version), in Blackboard under Admin Panel > System Configuration > File Size Limits. Then test it with your largest file before the deadline, not during it.

These are starting points, not guarantees. The sizes depend on the file, so check the result against your platform’s limit before you rely on a setting. The codec is the one real choice: H.265, Smol’s default, usually makes smaller files, and H.264 plays on more devices.

As a safety margin, aim for about 70 percent of the stated limit. That rule of thumb comes from our guide to PDFs that are too big to upload, which explains that upload portals can count the encoded upload; we have not tested it on an LMS. On H.264 against H.265, our post covers the trade, including full browser support of 97.26% for H.264 against 16.94% for HEVC, with another 76.59% partial (caniuse data, 27 September 2026). The email video guide notes that H.265 on Windows needs Microsoft’s HEVC decoder, which has a paid Store listing at $0.99. Students on a school-issued Windows laptop should receive H.264, and so should anything you post for the whole class.

Start by knowing what you recorded. The University of Illinois estimates about 20 MB an hour for a Zoom local recording of a shared screen and about 200 MB an hour for video, and calls both approximations. A native Mac screen recording of a Retina display is a different animal. Ours ran at roughly a megabyte per second, so a 50-minute capture is near 3 GB before editing.

For a sense of scale against a cap, James Madison University puts Canvas Studio’s 10 GB at roughly 500 minutes of 1080p video. That works out to about 20 MB a minute, so by their ratio a 500 MB cap holds about 25 minutes. That is arithmetic from their figure, not a measurement of ours.

In our screen-recording measurements (Smol 1.0.34, an M2 Pro, 26 September 2026), a 56,384,195-byte, 60-second recording became 3,691,160 bytes at Smol’s default H.265 settings, 93.5% smaller, in 38.4 seconds. With resolution set to 1920 it became 1,399,221 bytes, 97.5% smaller, in 16.3 seconds. We did not test camera footage of a classroom, so do not expect a slide-lecture result from it.

Three limits on those numbers. They are H.265 results, and we did not measure H.264 on this recording. The capture had no audio track, and a narrated lecture does; audio adds bytes of its own (by bitrate times time, an hour at 64 kbps is 28.8 MB and an hour at 128 kbps is 57.6 MB). It was also one clip on one Mac.

Do these before you compress

• Cut dead time first. A stream-copy cut re-encodes nothing, so the frames that remain are the originals. In our test, a stream-copy cut of the first 5 seconds of a 10-second clip, made with a command-line tool rather than Smol, left 48.8% fewer bytes, simply because half the clip was gone, so your saving depends on how much you cut. See reducing video size without losing quality for the command. Smol itself does not trim. Apple’s QuickTime Player guide lists trim among its edits; we did not test whether its trim re-encodes.
• Compress from the original, once. Repeated passes at the same setting cost quality: in a test with a command-line encoder (H.265, CRF 28, a 10-second 1080p clip, not Smol), the VMAF score fell from 90.03 after one pass to 77.37 after four. Keep the master and re-encode from it every time.
• Look at the smallest text. If a slide has 11-point code or a dense spreadsheet, open the output and read it. If it fails, keep the resolution and raise quality instead.
• Ask whether the file belongs in the LMS at all. Reading blocks direct video upload to Blackboard and sends it to YuJa, and Miami suggests other upload methods such as Kaltura for files over its Blackboard cap. Bowling Green encourages instructors to host class recordings in the service that created them, such as Zoom or Teams.

Our tested guide to compressing video on Mac compares the four ways to do it. For a semester of weekly recordings, batch compression means one drop for the whole folder.

A scan is a stack of photographs. Our three-page test scan was 5,017,560 bytes and held no searchable text, so there was nothing to search or copy. Size is the first reason it bounces; a scan with no text layer is the second problem for anyone who needs to search it.

The fix is an order of operations. Add the text layer first, then compress. In our scanned-PDF measurements, the scan was OCR’d with a free command-line tool, which gave 5,032,225 bytes, and Smol’s Large preset then gave 624,925 bytes at 164 PPI with all 1,405 words still searchable. Every preset kept all 1,405 words, because search reads the text layer, not the picture. A chain of that free OCR tool followed by Smol’s Medium preset reached 288,609 bytes, 94.2% smaller than the scan, but at 109 PPI. Smol does not OCR; that guide shows the free tool.

The last two rows are the warning. OCR run on the compressed pages still read 96.8% of the words at 82 PPI and failed at 55 PPI, where it recovered 1.42%. For anything with body copy, stay at or above 150 PPI. The presets are long-edge pixel caps, so the PPI you get depends on page size.

Student submissions follow the same path. An iPhone can save photos as HEIC; compress one with output JPG rather than converting, because converting ignores the quality setting. The HEIC to JPG guide covers the batch case. If a course needs a PDF of the pages, the email PDF guide covers shrinking one. For a department that sends large batches, batch PDF compression handles a whole folder in one drop.

Shrink what is inside the deck, not the deck. On our synthetic test deck, built from generated photos and a generated clip, 40,973,496 of its 41,010,934 bytes (99.9%) sat in ppt/media: six 4,032 x 3,024 photos and one video. Slides, layouts and text came to under 30 KB.

The method, described in our PowerPoint guide: compress the pictures and the video, then put them back. Both steps matter, because picture compression alone never touches an embedded video.

For next semester, do it in the other order. Compress the photos and the video before they go onto a slide, and the deck stays small without a rescue step. Course quotas are finite (1 GB at FSCJ, 2 GB at BGSU), and FSCJ’s post on PowerPoint storage offers two ways out: export the deck as a PDF, which is much smaller but loses audio, video and the slide effect, or link a copy kept in OneDrive, which does not count against course capacity.

1. 1

   Find the limit and set the target

   Look up your platform’s figure in your school’s IT pages or the table above. Multiply by 0.7 for a safety margin; that is a rule of thumb from our PDF upload guide, not something we tested on an LMS.

2. 2

   Trim before you compress

   Cut the dead minutes at the start and end of a recording in the editor you already use, since Smol does not trim. Keep the untrimmed original, and treat the trimmed file as the master you compress once.

3. 3

   Drop the files or the folder into Smol

   Drag a whole semester folder onto the window. Videos, PDFs and photos can sit in one batch, and each file shows its own progress and savings.

4. 4

   Pick the setting from the table

   Choose the codec, quality and resolution for video, a preset for PDFs, or output format and quality for photos. Save the combination as a preset on that Mac so the next batch can reuse it.

5. 5

   Run it and read the per-file results

   By default, Smol writes a copy next to each original with a _compressed suffix. In a direct compress job, if compressing would make a file larger, it keeps the original.

6. 6

   Check the copy before you upload it

   Play a minute of the video and read the smallest text. For a PDF, press Command-F and search a word. Compare the size with your target.

7. 7

   Upload the compressed copy

   Submit or attach the _compressed file. Keep the original until the course is over.

Two shortcuts help with repeat work. The Finder Quick Action puts compression on the right-click menu. A watched folder can compress every new recording that lands in it, but it has a known defect: it can make already-optimized files larger, so point it only at a folder of fresh, unoptimized exports.

If you compress one video a term, use QuickTime Player and stop reading. Smol is aimed at the folder case: a mix of video, PDFs and photos in one batch. The full video comparison is in how to compress a video on Mac, and the PDF field is ranked in the best PDF compressor for Mac.

Smol compresses on the Mac in front of you. Nothing is uploaded, there is no account and there is no Smol server in the path, so a graded paper or a recorded seminar is not sent to a third party to shrink it. Image compression strips metadata by default, which removes GPS coordinates from a student’s phone photos; see stripping GPS from photos.

Be exact about what that does and does not cover. We make no compliance claim of any kind. Your institution decides which tools may touch student records, and that decision rests with your policies and your IT or records office. Smol does not redact. Removing a PDF’s document properties is a separate operation and, as our metadata guide shows, can be reversed with a free tool unless the file is rewritten afterward. For files that must stay confidential, see Smol for confidential documents.

Solo is $29 once for one Mac. Team is $49 once for three licenses, one Mac each, with seats managed from an admin dashboard. Enterprise is $20 per seat, once, for 5 to 500 seats, managed from one dashboard. Updates are free, and there is no subscription or per-file quota. We publish no separate education price, so those are the numbers; details are on the pricing page.

Two facts matter to a purchasing office. There is no free trial and purchases are not refundable, so confirm your machines first: Smol needs macOS 13 or later on Apple Silicon, or macOS 14 or later on Intel, and it runs only on Mac. For a lecture-capture room or a course-production team, the practical gain is consistency. Each Mac keeps its own presets, so a department gets consistent settings by writing them down (codec, quality, resolution, PDF preset) and having each instructor recreate the preset.

For video-heavy courses see Smol for video delivery. A communications office that publishes campus photos and video alongside course material may also want Smol for marketing teams.

• Long lecture video that belongs in a media platform. If your school runs Kaltura, YuJa, Studio or similar, upload the original there and let the platform stream it. Miami suggests options such as Kaltura for files over its cap, and Reading sends all video to YuJa.
• Students on Windows or Chromebooks. Smol is macOS only. HandBrake lists Linux, Mac and Windows, and FSCJ walks through it with its “Vimeo YouTube 720p30” preset for Canvas Studio. We have not tested a method for Chromebooks or phones.
• Scans that need OCR. Smol does not OCR, and it does not edit, sign, merge or split PDFs. Run OCR first with the tool named in our scanned-PDF guide, then compress.
• Trimming a recording. Smol has no trim. Cut the dead time in an editor or QuickTime Player first.
• The deck itself. Smol does not open a .pptx and shrink it in place. It compresses the photos and video that go into one.
• A single video, once. QuickTime Player’s Export As is already installed, and for one clip the wasted bytes do not matter.
• Anything automatic inside the LMS. Smol is a desktop app, not a Canvas, Moodle or Blackboard plugin. If uploads must be compressed on a server, that is the Smol API or your platform’s own transcoding.
• Redaction. Hiding a student’s name on a PDF needs a redaction tool. Smol does not redact, and stripping metadata is not redaction.