Optimizing SCORM packages: reducing file size for faster training

A SCORM package is a zip file containing all the content a participant sees: slides, videos, images, audio and the technical files for communicating with Pluvo. The larger that package, the longer it takes before a participant can start the training, and the greater the chance of upload problems.

What is the recommended file size?

The common guideline in e-learning is a maximum of 100 MB per SCORM package. Packages above 100 MB can technically be uploaded, but you'll notice the difference in load time — especially for participants on mobile or with a slower network.

For reference:

The file size of your package is determined mainly by videos, images and audio. Text and technical SCORM files are negligibly small.

Why does size matter so much?

Upload. Large files are more likely to fail during upload, especially over an unstable internet connection. A 400 MB package is far more vulnerable than a 60 MB one.

Load time for participants. A SCORM package is not streamed but loaded in full before the training starts. With a 200 MB package, a participant on a 4G connection can easily wait 30 seconds or more. On a poor wifi network, that can stretch to minutes.

Mobile use. More and more participants follow training on their phones. On mobile, every megabyte counts. A large package also eats into their data usage.

Storage and management. Multiple large SCORM packages quickly fill up your academy and slow down management.

How do you compress a SCORM package?

Video is by far the biggest culprit. Images come next. Audio is a distant third.

Video

Videos account for 80–95% of the file size in most SCORM packages. This is where the biggest gains are.

Codec and container

Always use H.264 (MP4) as the video codec. H.265 is smaller but not compatible everywhere. Avoid MOV, AVI or WMV — these are larger than necessary.

Resolution

A higher resolution sounds better, but for e-learning on a laptop or phone you'll barely notice the difference between 720p and 1080p.

Bitrate

The bitrate determines how much data is stored per second. For e-learning, these guidelines apply:

For comparison: an unedited video from a screen recording or camera easily sits at 15–50 Mbps. That's 10x more than needed.

Compressing video on Windows

Option 1: Handbrake (free, recommended)

handbrake.fr works on Windows, Mac and Linux and is the most widely used tool for video compression.

1. Open Handbrake and drag your video file into it
2. Under Presets, choose "Fast 1080p30" or "Fast 720p30" as a starting point
3. Go to the Video tab: set Encoder to H.264, Encoder Preset to Medium
4. Set Constant Quality (RF) to 22–26. RF 22 = good quality, RF 26 = smaller file
5. Adjust the resolution under Dimensions if you want to reduce it
6. Click Start Encode and export as MP4

A 150 MB video is often reduced to 20–40 MB this way, without visible loss of quality.

Option 2: VLC Media Player (free, already on many computers)

VLC can also convert, handy if you already have it.

1. Go to Media → Convert/Save
2. Add your video file and click Convert/Save
3. Choose the profile: Video – H.264 + MP3 (MP4)
4. Click the wrench button next to the profile to adjust the bitrate and resolution
5. Set the video bitrate to 1000–2000 kb/s for 720p
6. Choose a destination and click Start

Option 3: Clipchamp (free, built into Windows 11)

Windows 11 comes with Clipchamp as standard. No download needed.

1. Open Clipchamp from the start menu
2. Create a new project and import your video
3. Drag the video onto the timeline
4. Click Export and choose the quality: 480p, 720p or 1080p
5. Clipchamp automatically exports as MP4 with reasonable compression

Clipchamp gives less control over the bitrate than Handbrake, but it's the fastest option for simple resizing.

Compressing video on Mac

Option 1: Handbrake (free, same as Windows)

Works identically on Mac. Download from handbrake.fr and follow the same steps as above.

Option 2: QuickTime Player (free, standard on every Mac)

QuickTime is already on your Mac and can export videos at a lower quality.

1. Open your video file in QuickTime Player
2. Go to File → Export As
3. Choose 720p or 480p
4. Save as MOV or MP4

QuickTime offers little control but works fast. If you want more control over the output, use Handbrake.

Option 3: iMovie (free, standard on Mac)

iMovie is primarily an editing tool but also exports compressed videos.

1. Create a new project and import your video
2. Drag the video onto the timeline
3. Go to File → Share → File
4. Choose the resolution (720p or 1080p) and quality (High or Medium)
5. Click Next and save

Option 4: FFmpeg via Terminal (free, advanced)

For those not afraid of the terminal: FFmpeg is the most powerful option and gives full control.

ffmpeg -i input.mp4 -vcodec libx264 -crf 23 -preset medium -acodec aac -b:a 128k output.mp4

• -crf 23: quality setting (18 = high quality, 28 = smaller file)
• -preset medium: balance between compression speed and file size
• Install via Homebrew: brew install ffmpeg

FFmpeg is also available on Windows via ffmpeg.org.

External video hosting as an alternative

Considering a video larger than 50 MB? Host that video externally (on Vimeo or a similar service) and load it into your course via an embed. Your SCORM package then becomes much smaller, and the video streams instead of loading in full first.

Downside: the participant needs an internet connection, including for offline use. With Pluvo, offline use does not apply, so this is usually the wisest choice for large videos.

Images

Use the right format

A PNG of a photo is always larger than a JPG of the same photo — sometimes two to five times as large. Use PNG only for images with transparency or sharp edges.

Resolution

Images in a course are displayed on screens 1280–1920 px wide. So you never need an image 4000 px wide. Set the width to a maximum of 1600–1920 px. For images next to text, 800–1200 px is more than enough.

Online tools (platform-independent)

TinyPNG / TinyJPG

tinypng.com compresses PNG and JPG files without visible loss of quality. Drag your files in and download the compressed versions. An 800 KB image is reduced to 200–300 KB on average. Maximum 20 files at a time in the free version.

Squoosh

squoosh.app lets you visually compare the compression before you export. You see the original on the left and the compressed version on the right. It also supports WebP, which is even more compact than JPG.

Compressing images on Windows

Option 1: Paint (built in, basic)

Open the image in Paint, go to Image → Resize, set the width to a maximum of 1600 px and save as JPG.

Option 2: IrfanView (free, powerful)

irfanview.com is a lightweight image editor with excellent batch export capabilities.

1. Open your image
2. Go to Image → Resize/Resample and adjust the resolution
3. Save via File → Save As, choose JPG and set the quality to 70–80%
4. For multiple files at once: File → Batch Conversion

Option 3: GIMP (free, advanced)

GIMP gives full control over export quality and resolution. When exporting, go to File → Export As, choose JPG and set the quality slider to 70–80.

Compressing images on Mac

Option 1: Preview (built in, fast)

Preview comes standard on every Mac.

1. Open your image in Preview
2. Go to Tools → Adjust Size to lower the resolution
3. Go to File → Export and choose JPG
4. Set the quality slider to 70–80%

For multiple files: select them all in Finder, open them together in Preview, select everything in the sidebar and export as a batch.

Option 2: Compressor.io (online, free basic version)

compressor.io compresses JPG, PNG, SVG and WebP. It shows the difference in file size right after upload. Maximum 10 MB per file in the free version.

Audio

Audio is rarely the biggest culprit, but it can add up in long courses with voice-over.

Format and bitrate

Always use MP3 for spoken audio. WAV and AIFF are uncompressed and much larger.

A 30-minute audio file at 128 kbps is about 28 MB. At 96 kbps that's 21 MB.

Compressing audio on Windows and Mac

Option 1: Audacity (free, Windows and Mac)

audacityteam.org is the most widely used free audio editor.

1. Open your audio file in Audacity
2. Go to File → Export → Export as MP3
3. Set the bitrate: 96 kbps for voice-over, 128 kbps for music or interviews
4. Save

Option 2: VLC (free, Windows and Mac)

VLC also converts audio. Go to Media → Convert/Save, add your audio file, choose an MP3 profile and adjust the bitrate via the wrench button.

Option 3: Online Audio Converter (online, no installation)

online-audio-converter.com works in the browser. Upload your file, choose MP3 as the output format, set the bitrate to 96 or 128 kbps and download the result.

Removing unused files

Authoring tools such as Articulate Storyline, Rise and iSpring automatically add files to your SCORM package: language files, interface elements, fallback assets. Not all of those files are always used.

If you know what you're doing, you can unpack the zip file, check its contents and remove unused files. This is an advanced step. Only do this if you thoroughly test the package afterwards — removing the wrong file can break the training.

For most users it's safer to adjust the export settings via the authoring tool. In Articulate Storyline, for example, you can choose which output options to include.

Splitting into multiple packages

A 500 MB course doesn't have to be a single SCORM package. You can divide the content into several smaller packages and place them as separate components in the learning journey in Pluvo.

Advantages:

• Each package loads faster
• Participants can stop and resume per component
• Uploading is easier

Downside: progress is tracked per package, not as a single whole. Consider this on a per-course basis.

Step-by-step plan for a new SCORM package

1. Gather your source files and check the size of all videos and images before you start building.
2. Compress videos via Handbrake to H.264, a maximum of 2–4 Mbps for 1080p.
3. Optimize images via TinyPNG or Squoosh.
4. Export audio as MP3 at 96–128 kbps.
5. Publish the SCORM from your authoring tool.
6. Check the file size of the zip file before you upload it. If it's above 100 MB, find the largest file and tackle that.
7. Test the package after upload in Pluvo before giving participants access.

Frequently asked questions

What is the maximum SCORM size in Pluvo?

Pluvo does not publish a hard upper limit. The practical recommendation is to stay under 100 MB for the best user experience. Do you have a package that's much larger and are you seeing problems with uploading or playback? Then get in touch via the chat in your academy.

Can I host videos externally and still use SCORM tracking?

Yes. The tracking runs via the SCORM standard and is independent of where your videos are hosted. Embed your video in your slide via a URL, and the tracking works as normal.

My SCORM package is already built and is 350 MB. What now?

Open the zip file, find the largest files and compress them as described above. Add the compressed versions back in and export again. Or: upload the package and test how it loads — if the load time is acceptable, it doesn't necessarily need to be smaller.

Pluvo supports SCORM 1.2 and SCORM 2004. Does the version make any difference to file size?

No. The version determines which tracking data is exchanged, not the file size. For progress reporting in Pluvo, we recommend SCORM 2004.

Updated on: 12/06/2026