Issue

You may intermittently receive 404 Not Found responses when attempting to access media URLs provided in Twilio webhooks, even though requests are properly authenticated using the Account SID and Auth Token. The same media URLs typically work moments later without any code changes.

Product

Twilio Programmable Messaging
Twilio Programmable Voice

Cause

This behavior is not related to authentication. Instead, it is caused by temporary media availability delays after a webhook is delivered.

When Twilio sends a webhook that includes a media URL, the webhook may be delivered before the media object is fully propagated and accessible across Twilio’s media storage infrastructure. During this brief window:

• Authenticated requests to the media URL may return 404 Not Found.
• Subsequent requests to the same URL usually succeed once propagation completes.

In reported cases, this behavior began suddenly (for example, after December 8th, 2025) without any customer-side code or infrastructure changes, indicating a possible internal change or timing shift within Twilio’s media pipeline.

Resolution

To handle intermittent media availability delays:

1. Implement retries with backoff
   • When receiving a 404 from a media URL, retry the request after a short delay (for example, 1–3 seconds).
   • Use incremental backoff and limit retries to avoid unnecessary load.
2. Log media fetch timing
   • Capture timestamps for:
     • Webhook receipt
     • Initial media fetch attempt
     • Successful media retrieval
   • This helps quantify propagation delay and identify trends.
3. Avoid immediate hard failures
   • Treat an initial 404 as a transient condition rather than a permanent error when accessing Twilio-hosted media.
4. Escalate if frequency increases
   • If intermittent 404s occur frequently (for example, dozens per day), gather:
     • Media URLs affected
     • Associated Message or Call SIDs
     • Timestamps (with timezone)
   • Provide these details to Twilio Support so the issue can be escalated to Engineering for investigation.

Additional Information

• All media requests must still be authenticated; however, correct authentication does not guarantee immediate availability.
• This behavior differs from authentication-related 404s, which would fail consistently rather than intermittently.
• Browser playback issues (for example, HEVC codec limitations in Chrome for iPhone-recorded videos) are unrelated and should be handled separately at the client level.