Construct 3 | How to integrate with Kongregate

Construct 3 exports HTML5 games that are generally compatible with Kongregate with minimal modification. For the best experience, developers should:

• Export using the HTML5/Web export option
• Use a ZIP export
• Ensure the game runs correctly in a modern desktop browser before uploading
• Avoid requiring unsupported browser permissions or external launchers
• Test the uploaded build on Kongregate before making the game public

Which export option should I use in Construct 3?

Use:

Menu → Project → Export → Web (HTML5)

Recommended settings:

• Export as ZIP
• Minify script: Enabled
• Use worker scripts: Enabled (if your game supports it)
• Optimize for size: Enabled
• Include unused files: Disabled

After export, upload the generated ZIP directly to Kongregate.

Do not re-zip the exported contents manually unless necessary, as altering the folder structure can break loading paths.

Integrating the Kongregate API

What file should I upload to Kongregate?

Upload the ZIP file generated directly by Construct 3.

Your ZIP should contain:

• index.html
• JavaScript/runtime files
• Asset folders
• Audio/image resources

The index.html file must exist at the root level of the ZIP archive.

Does Kongregate support Construct 3 games on mobile?

Kongregate supports browser-based HTML5 gameplay and should be compatible with mobile web. You should design and test for both desktop web compatibility, and include responsive layouts and touch control options for mobile web play.

Recommended:

• Responsive UI scaling
• Touch-friendly controls
• Landscape/portrait handling
• Performance testing on lower-end devices

How should I handle fullscreen mode?

Construct 3 fullscreen support generally works well on Kongregate, but browser security restrictions may require fullscreen to be triggered only from direct user interaction.

Best practices:

• Add a visible fullscreen button
• Trigger fullscreen from a click/tap event
• Avoid auto-entering fullscreen

What aspect ratio works best?

Recommended aspect ratios:

• 16:9
• 16:10
• Responsive scaling layouts

Avoid hardcoding extremely small resolutions or fixed browser window sizes.

Common recommended minimum dimensions:

• 1280×720
• 960×540

How can I improve loading performance?

To improve player experience:

• Compress audio assets
• Optimize image sizes
• Use sprite sheets where appropriate
• Avoid unnecessarily large video files
• Enable Construct 3’s script minification and optimization settings

Large initial downloads can negatively impact player retention.

Should I preload all assets?

No. Large preload screens can increase abandonment rates.

Recommended approach:

• Preload only critical gameplay assets
• Lazy-load secondary content where possible
• Stream optional audio or cosmetic content later

Does Kongregate support cloud saves or local storage?

Construct 3 local storage features generally work normally in browser environments. However:

• Avoid relying exclusively on browser local storage for critical progression
• Handle save failures gracefully
• Consider backup/export options for long-term progression systems

Players may clear browser data or switch devices

How should I implement audio?

Browser audio systems can behave differently depending on device and browser policies.

Best practices:

• Start audio only after user interaction
• Provide volume/mute controls
• Test audio resume behavior after tab switching
• Avoid excessively large music files

Publishing and testing

Do not test your API integrations locally. The Kongregate API requires a CORS handshake with Kongregate's live servers.

You can test your new game upload before submitting for publishing on the 'preview' page in the Developer Portal.

Test guest play, user login and stat submission within the live environment to verify that everything works correctly for players.

Common issues include:

• Incorrect ZIP structure
• Missing files
• Case-sensitive filename mismatches
• External resources blocked by browser security
• Hardcoded localhost paths
• Unsupported third-party plugins

Always test using:

• A hosted environment
• HTTPS
• Multiple browsers (including mobile web)

Are third-party Construct 3 plugins supported?

Many third-party plugins work correctly, but compatibility depends on browser support and implementation quality.

Before launch:

• Test every plugin in a production export
• Verify compatibility with HTTPS environments
• Confirm plugins do not require unsupported native integrations

Unsupported or poorly maintained plugins are a common source of issues.

Can I use advertisements or external monetization SDKs?

Kongregate provides an ecosystem that includes advertising, in-app purchases, accounts, leaderboards and achievements.  As such, no external accounts, advertisements or monetization systems are permitted (see SUBMISSION | Checklist -- review before uploading a game). 

Note: advertising is provided around your game on the site, and for which revenue is shared. Incentivized ads should be available Q3 2026. 

Also see STANDARDS | Developer Content Standards

What browsers should I test?

At minimum:

• Google Chrome
• Microsoft Edge
• Firefox
• Safari (if supporting macOS/iOS browsers)

Test:

• Gameplay
• Saving/loading
• Audio
• Fullscreen
• Input responsiveness
• Performance over longer sessions
• Performance on mobile web

How should I prepare updates?

When updating your game:

• Increment internal version numbers
• Preserve save compatibility where possible
• Re-test exported builds before uploading
• Verify cache behavior after deployment

Major save-breaking updates should be clearly communicated to players.

What are the most common launch mistakes?

Common issues include:

• Uploading the wrong ZIP structure
• Not testing on a hosted environment
• Unoptimized assets causing long load times
• Missing mobile/touch considerations
• Audio failing due to autoplay restrictions
• Save systems failing silently
• Third-party plugin incompatibility

A short pre-launch QA pass across multiple browsers can prevent most launch-day problems.

Support 

SUBMISSION | Checklist before uploading a game

STANDARDS | Developer Content Standards

ASSETS | How can I safely use third-party assets (art, music, code) in my game?

TOOLS | Can developers use AI tools when building games?

DOCUMENTATION | What documentation must developers follow?

HELP | I have questions! 

Developer Guidance Disclaimer