fileSize

fileSize · Not mentioned by Google

Appears in

• SoftwareApplication

What is it?

fileSize specifies the download size of a software application as a human-readable string with a unit, such as "38MB" or "1.2GB". This helps users understand the storage and bandwidth requirements before downloading.

Why this matters for AEO

When a user asks "How big is the VLC download?", AI engines can pull the fileSize value to give a precise answer. This is especially relevant for mobile users on limited data plans or users comparing lightweight alternatives.

What the specs say

Schema.org: Text. Size of the application / package (e.g. 18MB). In the absence of a unit (MB, KB etc.), KB will be assumed. View on schema.org

Google: Not listed in Google's structured data documentation for SoftwareApplication. View on Google

How to find your value

Check the actual file size of your downloadable installer or package. Find this in:

• Your build output — File properties of the .exe, .dmg, .apk, or .zip
• App Store Connect — Binary size listed in your app dashboard
• Google Play Console — APK/AAB size in the release dashboard
• GitHub releases — File size shown next to each release asset

Always include the unit. Schema.org defaults to KB if no unit is provided.

Format and code

The value is a text string with the size and unit.

{
  "@context": "https://schema.org",
  "@type": "SoftwareApplication",
  "name": "VLC media player",
  "operatingSystem": "Windows, macOS, Linux, iOS, Android",
  "applicationCategory": "MultimediaApplication",
  "softwareVersion": "3.0.23",
  "fileSize": "38MB",
  "downloadUrl": "https://www.videolan.org/vlc/"
}

Valid values:

"fileSize": "38MB"
"fileSize": "1.2GB"
"fileSize": "350KB"
"fileSize": "14mb"

Case does not matter for the unit, but uppercase (MB, GB, KB) is standard.

Webflow implementation

Static pages

Add in Page Settings > Custom Code (Before </body> tag):

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "SoftwareApplication",
  "name": "VLC media player",
  "fileSize": "38MB",
  "operatingSystem": "Windows, macOS, Linux",
  "applicationCategory": "MultimediaApplication",
  "offers": {
    "@type": "Offer",
    "price": 0,
    "priceCurrency": "USD"
  }
}
</script>

CMS template pages

Store the file size as a plain text field in your CMS collection (e.g., "45MB"). Reference it in your template's JSON-LD block. Update when you release a new version.

In Schema HQ

Your CMS file size field is mapped to fileSize automatically. For static pages, enter the value directly in the editor.

Real examples

VLC media player ):

{
  "@context": "https://schema.org",
  "@type": "SoftwareApplication",
  "name": "VLC media player",
  "operatingSystem": "Windows, macOS, Linux, iOS, Android",
  "applicationCategory": "MultimediaApplication",
  "softwareVersion": "3.0.23",
  "fileSize": "38MB",
  "downloadUrl": "https://www.videolan.org/vlc/"
}

Note: videolan.org does not implement JSON-LD structured data. This example is constructed from actual product data (version 3.0.23, Windows installer approximately 38 MB).

BuiltVisible template (from builtvisible.com):

{
  "@context": "https://schema.org",
  "@type": "SoftwareApplication",
  "name": "[App Name]",
  "fileSize": "14mb",
  "downloadURL": "[download url]",
  "operatingSystem": ["[OS 1]", "[OS 2]"],
  "applicationCategory": "[category]"
}

Related fields

• downloadUrl — Where to download the file
• softwareVersion — Which version this size applies to
• operatingSystem — Platform (file size often varies by OS)

FAQ

Should I include fileSize for web apps?

Generally not. fileSize is most useful for downloadable software. Browser-based apps have no meaningful file size to report.

What unit should I use?

Use the unit that makes the number easy to read. Under 1 MB, use KB. Between 1 MB and 1 GB, use MB. Over 1 GB, use GB. Always include the unit explicitly; omitting it causes schema.org to default to KB.