Skip to main content

How to Start a Live Stream in Castr

How to create a new live stream project. You’ll also explore the features to optimize your stream.

Written by Govinda Sunil

Use this guide to create a live stream project to stream to your website with embed player and multistream to 30+ social platforms at once.

In this article

Create a new Live Stream

1. Log in to your Castr account

2. In the left sidebar, click Livestream, then click Create New (top-right).

On the 7-day trial? If you don't have a subscription yet, the panel offers Activate Trial (7-day trial)

3. Enter a Stream Name, then choose a Hosting Region. Pick the location closest to where you'll broadcast from for the best ingest quality. For example, if you're in Brazil choose South America; if you're in Chicago choose US East.

4. Click Create Livestream. You'll be taken into the stream's workspace.

What’s in the dashboard?

This is the control center for your Livestream: get your stream key, configure your encoder, grab an embed code, add destinations, and more.

At the top you'll see a stats bar (Bandwidth, Viewers, Bitrate, Resolution, Codecs, Audio Bitrate) that comes alive once you're live, a row of tabs (Destinations, Analytics, Live To VOD, Paywall, Alerts, Advertising, Settings, Backup), and a right-hand panel with Source Setup, Playback, and Monitoring.

Preview player

Once you start sending your stream to Castr, you’ll be able to see it live in the preview player.

Set up your source

Open the Source Setup tab on the right and choose how video will reach Castr. First confirm your region (changing it updates your ingest URL), then pick a mode.

Publish - RTMP / RTMPS (most common)

  1. Select the Publish tab, then the RTMP protocol tab (or RTMPS for an encrypted connection).

  2. Copy the Primary RTMP server URL — e.g. rtmp://<region>.castr.io/static.

  3. Copy the Streaming Key (click the eye icon to reveal it, or the copy icon). Use Reset Password to rotate the key if needed.

  4. Paste the server URL and stream key into your encoder's output settings and start streaming. Castr detects the input and the stats bar comes alive.

See our guide on connecting OBS to Castr, and the difference between RTMP and SRT.

Publish — SRT

On the SRT tab, copy the full SRT publish string into your SRT-capable encoder. Optionally turn on Encrypted SRT, set a passphrase, and click Save to require encryption.

Publish — WHIP (WebRTC)

On the WHIP tab, copy the HTTPS WHIP endpoint and use it in a WHIP-compatible encoder or browser source for low-latency WebRTC ingest.

Pull

On the Pull tab, paste a source URL (HLS, RTMP, RTSP, MPEG-TS) and click Save. The status shows Connecting, then Connected once Castr locks onto the feed.

Webcam

On the Webcam tab, allow camera and microphone access, choose your devices, and start broadcasting — no encoder required. (Not available on mobile.)

Linked

On the Linked tab, click Select Source and pick another of your Castr streams to use as this stream's input.

Get your embed & player link

Open the Playback tab to get the player for your website. Make sure Enable Playback is on, then choose a player format:

  • Normal — standard HLS player (default).

  • LL — Low Latency, under ~15 seconds (plan-dependent).

  • ULL — Ultra Low Latency, powered by Sub-Second Streaming.

  • Audio — an audio-only player.

To embed the player, choose Responsive or Fixed size, copy the generated iframe code, and paste it into your website's HTML. You can also copy a Direct Player Link to share the player without embedding, or grab the HLS URL (on the Normal tab) to play the stream in a third-party player.

Destinations

In your stream dashboard, click Add destination to add publish destinations

Publish destinations are the platforms that you want to stream live on simultaneously. The number of destinations you can add depends on your subscription plan.

  1. Click Add destination.

  2. Pick a platform — Facebook, YouTube, Twitch, LinkedIn, X, Instagram, TikTok, custom RTMP/SRT, or Internal Workflow to send to another Castr stream.

  3. Connect it either by linking your account (OAuth) or with Server/Key (paste the platform's RTMP/SRT server and key).

  4. Fill in any platform-specific fields, click Create Platform, then toggle the destination on.

You can also organize destinations into groups and accept guest destinations.

To add another platform, repeat these steps. Then toggle the platforms on.

Analytics

View all traffic data received from your livestream. Learn more in the analytics dashboard guide and stream health charts guide.

You can also monitor the health of input feed from encoder to Castr. You can learn more about stream health charts here.

Live to VOD

Turn on Cloud Recording in the Live To VOD tab to automatically record while you're live. Afterward, find recordings under Recorded Clips, where you can preview, Export to VOD (it becomes a hosted video in your Content Library), download the whole video or a selected range, or delete it. For full details, see this tutorial.

Paywall & Advertising

Paywall — monetize your livestreams directly with paywall. Learn more.

Advertising — run in-stream ads using a custom VAST tag or your own uploaded MP4, and set the placement and skip-after delay. Learn more.

Settings

The Settings tab lets you customize the HTML5 player and control access. Click Save after changing a setting.

Player Interface

  • Player Theme Color — pick an accent color for the player.

  • Offline Message — the message viewers see when the stream is offline.

  • Display Event Countdown — show a countdown to your scheduled start time.

  • Display Number of Viewers — show the real-time viewer count.

  • Custom Embed Poster & Watermark — upload your own poster image and logo, and set the watermark position.

Player Functions

  • Autoplay Embed Player — start playing automatically when the page loads.

  • Hide Audio Icon — hide the volume control.

  • Enable Embed Player Rewind — let viewers rewind live (30 min up to 4 hours, plan-dependent).

  • Delaying Stream on Embed Player — add a broadcast delay (mutually exclusive with rewind).

  • Enable Google Analytics — enter your GA ID for deeper insights.

  • Enable Chat — add a chat box to the player.

  • Enable Player Events — emit play/pause events for developers.

  • Enable Caption Support — show captions if your source includes them.

Security

Protect your content with password protection, geo/country blocking, geo whitelisting, and domain whitelisting (with an option to whitelist specific pages only).

Adaptive Bitrate

Adaptive Bitrate now has its own section. (It can't be changed while the stream is live — disable the stream first.) Turn on Enable Adaptive Bitrate so viewers automatically get the best quality their connection allows. You can also:

  • Set Custom FPS — 25 / 30 / 50 / 60 / Pass.

  • Customize the Bitrate Ladder — toggle individual renditions (Source, 1080p, 720p, 480p, 360p, 240p) and set each one's bitrate.

  • Set Audio Bitrate — 64 / 128 / 256 / 320 / 512 kbps.

Alerts

  • Notifications — turn on phone alerts to get an SMS if your stream goes down. Manage numbers under your account settings.

  • Webhooks — add a webhook name and URL, and Castr will call it on events such as stream start/stop to notify your own systems.

Backup & failover

Use the Backup tab to keep your stream running if your primary encoder fails. (Disable the stream first — backup can't be toggled while live or with a Linked source.)

  1. Turn on Enable Backup and confirm (your stream keys change when backup is enabled).

  2. Choose a mode: Encoder Level (a second encoder takes over automatically) or File Level (a backup VOD plays if the live input drops).

  3. For Encoder Level, copy both the Primary and Backup ingest URLs and point a second encoder at the backup ingest.

Start Castr

What's Next?

Did this answer your question?