Chartboost playable ads: requirements and specs

How Chartboost handles playable ads

Chartboost requires playable creatives to be built in MRAID Playable format. MRAID (Mobile Rich Media Ad Interface Definitions) is the IAB's standard interface for rich-media mobile ads — it's the same underlying spec that networks like AppLovin and Unity Ads build their playable support on, so an MRAID-compliant playable is a reasonable common denominator across several networks, not a Chartboost-only requirement.

Chartboost's Creative Formats documentation confirms MRAID support specifically as "MRAID 1.0 & 2.0" (represented in bid response fields as the API value [3,5]), and notes that this support covers "some" MRAID 2.0 methods rather than the full spec — worth checking directly against your build if you're relying on a less common MRAID 2.0 call.

File size guidance

The clearest number Chartboost publishes is in that same Creative Formats documentation, under HTML/MRAID end cards: Chartboost recommends limiting the full size of your creative to under 5 MB — and it defines that 5 MB as covering the ad markup plus any assets downloaded at rendering time, not just the initial HTML payload. That's a meaningfully different accounting than a network that caps only the initial ZIP or HTML file, so if your build lazy-loads any assets after first paint, those bytes count against the limit too.

Chartboost's Placement Types documentation lists where playables are supported: fullscreen display interstitials (as one of several HTML5/MRAID ad types alongside static and animated) and fullscreen rewarded placements (as an alternative to VAST video). Playables are not listed as a supported format for the smaller banner placements (320x50, 728x90, 300x250) — those are for static/animated HTML5/MRAID creatives only.

Close button and countdown behavior

Two specific timing details are published in Chartboost's Creative Formats documentation and are worth designing around: on an interstitial placement, Chartboost shows its own close button 5 seconds after the playable loads; on a rewarded placement, that default countdown is 20 seconds before the close button appears. In both cases, the close button is Chartboost's native UI, not something your creative renders itself — which lines up with the broader MRAID convention (used by most networks) that a playable should not draw or intercept its own close control.

What we could confirm, and what we couldn't

In the interest of not inventing anything: Chartboost's advertiser-facing documentation focuses heavily on the exchange/bidding side of playable delivery (for example, requiring specific OpenRTB bid-response fields to flag a creative as an MRAID playable) rather than publishing a simple, uploader-facing packaging spec the way some other networks do. We were not able to independently verify, from a live official source at the time of writing, an exact statement on:

• Whether Chartboost expects a single self-contained HTML file or a ZIP archive for playable submissions
• A specific required entry filename or folder structure
• The exact CTA/click-through method name Chartboost's playable uploader expects at runtime

Where we could confirm real numbers directly from Chartboost's documentation — the 5 MB size guidance, MRAID 1.0/2.0 support, and the 5-second/20-second close-button timing — we've stated them above with the specific figures. Where we couldn't verify a claim against a live official page, PlayableKit's converter makes the same choice most MRAID-based networks converge on: a single self-contained HTML file with click-through wired to the standard mraid.open() call. That's an engineering decision built on the common MRAID convention, not a line quoted from Chartboost's own spec, so confirm packaging details with your Chartboost account contact before a large campaign.

Networks PlayableKit supports today

Every one of these networks has its own click-through API, size limit, and packaging convention — and PlayableKit applies the correct one automatically from a single Unity Playworks/Luna export:

Test a Chartboost build today

Upload a Unity Playworks/Luna export and PlayableKit handles the click-through wiring, asset encoding, and package shape automatically. The free Playable Ad Validator checks your build for structural problems (missing entry files, broken inline scripts, missing engine assets), and the free Playable Size Checker tells you exactly how large your build is once assets are accounted for, which is directly useful against Chartboost's stated 5 MB guidance above. Neither tool requires a signup.

For more on what adapting a single Unity Playworks/Luna export for multiple ad networks actually involves, see our Unity Playworks/Luna alternative overview.