Free
$0
forever
- Monitors
- 1 stream
- Check interval
- Every 15 minutes
- Alerts
- Email to 1 address
- Audio settings
- Fixed defaults
- Also included
- Dashboard
Catch
dead air.
Silence detection for Icecast, Shoutcast and HLS radio streams. Check your audio now, then let SilenceAlarm check it on a schedule.
20-second audio check. No account needed.
Audio checkMP3 / Stereo
Illustrative example · choose a state
Left channel-22.4 dB
Right channel-23.1 dB
Audio is present
Both channels are above the example silence threshold.
Start free with one stream checked every 15 minutes. Pro checks from every minute, for $9/month.
Online can still be silent.
A stream URL can respond while listeners hear nothing. That is dead air. A muted encoder or a failed playout system can leave the connection working and the audio missing. SilenceAlarm checks the audio level as well as the connection.
Stream connectionHTTP 200
Audio levelSilent
Example: the URL responds, but the audio is below the silence threshold.
Know when it goes quiet.
An alert tells you which stream needs attention. A second message confirms recovery when a later check finds audio again.
SilenceAlarmExample
Silence detected
The audio level is below the silence threshold. Check your source and playout.
MonitorMain radio stream
SilenceAlarmExample
Audio restored
Audio is present again. The monitor has returned to a healthy state.
MonitorMain radio stream
Alerts follow scheduled checks. Free checks every 15 minutes; Pro from every minute. Detection and delivery take additional time.
Set up your stream checks.
Add the public stream URL and choose how often it should be checked. No studio installation.
Add your stream
Use the direct Icecast, Shoutcast or HLS stream URL. Try it in the free audio check first.
Choose the check
Pro lets you set the interval, sample duration and silence threshold. Free checks every 15 minutes with fixed settings.
Choose where alerts go
Receive email alerts when a check detects silence or an outage, and a follow-up when the stream recovers. Pro also includes mobile push.
Monitor settingsPro
Example configuration
- Stream URL
- https://radio.example/live.mp3
- Check interval
- 1 minute
- Audio sample
- 10 seconds
- Silence threshold
- −40 dB
- Notifications
- Email + mobile push
Made for radio streams
- Protocols
- Icecast, Shoutcast, HLS, HTTP, HTTPS
- Codecs
- MP3, AAC, OGG, Opus
- Threshold & sample
- Fixed on Free. Adjustable on Pro.
- Check interval
- 15 minutes on Free. 1–60 minutes on Pro.
- Alert channels
- Email on Free. Email and mobile push on Pro.
- Loudness
- EBU R128 loudness (LUFS) on Pro.
Choose your check interval.
Start with one stream. Move to Pro for more frequent checks and up to ten monitors.
| Free$0forever | Pro$9per month | EnterpriseCustomtalk to us | |
|---|---|---|---|
| Monitors | 1 stream | Up to 10 streams | Agreed scope |
| Check interval | Every 15 minutes | Every 1–60 minutes | By agreement |
| Alerts | Email to 1 address | Email + mobile push | Discuss your requirements |
| Audio settings | Fixed defaults | Adjustable threshold & sample | Configured to your needs |
| Also included | Dashboard | LUFS, reports & metadata audit | Integrations & support by agreement |
| Create a free monitor | Upgrade to Pro | Contact sales |
Pro
$9
per month
- Monitors
- Up to 10 streams
- Check interval
- Every 1–60 minutes
- Alerts
- Email + mobile push
- Audio settings
- Adjustable threshold & sample
- Also included
- LUFS, reports & metadata audit
Enterprise
Custom
talk to us
- Monitors
- Agreed scope
- Check interval
- By agreement
- Alerts
- Discuss your requirements
- Audio settings
- Configured to your needs
- Also included
- Integrations & support by agreement
Free requires a monthly email confirmation. Enterprise scope, integrations and service levels are agreed individually.
View all plan details
Free
- 1 monitor
- 15-minute check interval
- 1 email address
- Fixed silence threshold
- Dashboard
- Monthly email confirmation
- Community support
Pro
- Up to 10 monitors
- Check interval from 1 to 60 minutes
- EBU R128 loudness (LUFS)
- Reporting
- Metadata audit and export
- Email and mobile push
- Adjustable threshold and sample duration
- Priority support
Enterprise
- Pro features as a starting point
- Monitoring scope agreed individually
- Discuss SMS, API and webhook integrations
- Discuss recording and multi-region requirements
- Service levels and support agreed in writing
Before you start.
Find the right stream URL, troubleshoot silent audio and understand scheduled monitoring.
Contact usStream and audio
Why is my Icecast or Shoutcast stream online but silent?
A connected encoder can still send silence. Open the direct listener URL in a separate player. If it is silent there too, check the encoder’s audio input, muted mixer channels and the playout source. If only your website player is silent, check its mute and volume controls. A successful HTTP response or an updating track title does not prove that audio is present.
How do I find the direct URL for my radio stream?
Look for the public listening URL in your radio hosting panel. An Icecast URL includes the mountpoint, for example https://radio.example/live.mp3. For HLS, use the public .m3u8 playlist URL. Paste the listener URL into the audio test, rather than your station homepage, an embedded player page or the encoder’s source-login address. A stream URL does not always end in .mp3 or .aac.
How do I reduce silence alerts during quiet passages?
Compare the measured level with audio you know is valid, including speech pauses, song fades and quiet music. On Pro, a lower, more negative silence threshold can stop quiet programme audio from being classified as silence. Review the audio sample duration separately: it determines how much audio is analysed in a check, not a guaranteed continuous-silence delay. There is no single threshold that suits every station.
Is there a free online silence detector for radio streams?
Yes. The free live silence detector checks a public radio stream for 20 seconds without an account. It is useful for testing the URL and checking whether audio is present at that time. For recurring checks and email alerts, create a free account: Free includes one monitor checked every 15 minutes. A successful one-off test does not guarantee that the stream will stay healthy.
Monitoring with SilenceAlarm
How soon will I receive an alert?
An alert follows a scheduled check. Free checks every 15 minutes; Pro lets you choose 1–60 minutes. A problem that starts between checks may go undetected until the next one. Sampling, processing and notification delivery add time; these are not continuous checks.
Which streams can I monitor?
Use a publicly accessible Icecast, Shoutcast or HLS stream over HTTP or HTTPS. Supported codecs include MP3, AAC, OGG and Opus. Try the direct stream URL in the free check before setting up a monitor.
How are alerts delivered?
Free sends email to one address. Pro includes email and mobile push via ntfy. You can discuss additional integrations and notification requirements with us for Enterprise.
Can I adjust silence detection?
On Pro you can change the silence threshold in dB, the audio sample duration and the check interval. Free uses fixed settings and a 15-minute interval. A sample is a short check of the stream, not continuous listening.
Does this replace a studio silence detector?
It complements one. A studio detector monitors the local signal. SilenceAlarm checks the public stream URL from the cloud, so it can detect problems further along the delivery path.
Do I need to install anything?
No. Scheduled monitoring runs in the cloud. You need a public stream URL, an account and an email address for alerts. The 20-second test on this page works without an account.
How is my stream URL used?
SilenceAlarm uses the URL to connect to your stream and check its audio and availability. Use a public listening URL. For information about personal data, retention and service providers, read the privacy policy.
Start with one stream.
One monitor, email alerts and a check every 15 minutes. No card required.