It depends on what goes wrong and when.
- Our script is blocked or never loads. Your page shows whatever was there before SmartVideo. An existing Vimeo or YouTube embed still plays from Vimeo or YouTube, and a regular HTML video still plays its own file. You lose our player for that visit, not the video. Videos from your SmartVideo Library, and any other
<smartvideo>tags, show no player at all, because our script is what creates the player. - Our script loaded and replaced the embed, then playback fails. By then the original Vimeo or YouTube player is no longer on the page, so it does not come back automatically.
If the script never runs
Auto-conversion never edits the HTML your server sends. Your original embeds stay in your templates and database; our script swaps them for the SmartVideo player in the visitor’s browser.
If SmartVideo’s script (https://assets.swarmcdn.com/swarmcdn.js) is missing from the page or blocked, SmartVideo does not replace your page’s video elements:
- Existing Vimeo or YouTube
<iframe>embeds stay as written. The original service’s player loads as usual. - Existing HTML
<video>elements stay as written. Their original sources and controls stay in place. - SmartVideo Library videos and other
<smartvideo>tags show nothing. Our script is what turns the tag into a player, so without it no player or poster image appears.
The usual causes — a caching plugin delaying our script, a content-security policy blocking it, or a template missing the snippet — all stop our script before it runs, so your original Vimeo and YouTube embeds keep playing.
Some caching and speed plugins delay scripts until the visitor scrolls or clicks. In that case the original embed shows first, and SmartVideo replaces it once our script runs. That is a delay, not a failure.
Before a Vimeo embed is replaced
With Vimeo auto-conversion, SmartVideo checks whether the converted video is available on our CDN before replacing the native embed. If the converted copy is not available, the Vimeo embed stays in place and SmartVideo requests conversion. On WordPress, the plugin’s Legacy player (the default in plugin 2.4) skips this check and replaces Vimeo embeds right away, as it does YouTube. See Migrating from Vimeo to SmartVideo.
YouTube works differently. With YouTube auto-conversion on, SmartVideo replaces a YouTube embed straight away, even before our copy is ready, and plays the video from YouTube inside the SmartVideo player until then. This still needs our script, so it does not help when the script is blocked. YouTube conversion is best-effort. For a reliable source, download a copy you have permission to use and upload it to your Library. See Can I use YouTube videos?.
After an embed has been replaced
Once SmartVideo replaces a Vimeo or YouTube embed, the original player is no longer on the page. It is not hidden behind ours, waiting to take over. If our player fails after that, the page does not switch back to the original embed.
Until our copy is ready, a replaced YouTube embed plays from YouTube inside the SmartVideo player.
Library videos and <smartvideo> tags never had a Vimeo or YouTube embed behind them, so there is nothing to switch back to.
Troubleshoot a missing player
If nothing appears where a Library video should be, SmartVideo may not have loaded or finished starting. Check that the SmartVideo snippet is on the page, includes your Swarm CDN Key, and is not blocked by a caching or optimization plugin or your site’s content security policy. If you see the original Vimeo or YouTube player, the embed has not been replaced. That can mean our script has not run, auto-conversion is off, or a Vimeo video is still waiting for conversion. How do I know SmartVideo is working? shows how to confirm.
If you see the SmartVideo player but the video does not play, follow Video not playing: troubleshooting guide.
Keep a copy of your original video files somewhere you control. See Video backup best practices.
If you need help, email support@swarmify.com with the page URL and say whether you see the original player, a SmartVideo player with an error, or no player.
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