To stream vertical video to YouTube through Castr, create a Castr live stream, connect YouTube as a destination, and configure YouTube’s vertical format before going live. Castr receives and forwards your video; YouTube’s Live Control Room determines how viewers receive the vertical layout. For a separate portrait feed alongside a horizontal one, configure the encoder and route each format to its corresponding YouTube stream key.
What Castr does—and what YouTube controls
Castr is the routing step: you choose a source, add YouTube as a destination, and enable that destination. YouTube controls the vertical viewing experience and the relevant stream settings. Castr’s setup guide, dated August 4, 2026, documents source setup and YouTube destination connection (Castr’s live-streaming setup guide). Its multistream guide, dated May 17, 2023, describes sending an encoder feed to Castr over RTMP or SRT and then adding destinations; destination limits depend on the subscription plan (Castr’s multistream guide).
Do not assume that Castr automatically creates a separately composed portrait version of a horizontal feed. For one source adapted to vertical, use YouTube’s built-in dual-stream layout. For separately produced horizontal and portrait feeds, use an encoder workflow and confirm that each feed reaches its matching YouTube key.
Create a Castr stream and choose a source
- Create the live stream in Castr. Choose a hosting region when prompted.
- Set up the source. Castr documents Publish via RTMP/RTMPS and a webcam option. If you use an encoder, Castr’s multistream guide also describes sending a feed over RTMP or SRT. The exact options and labels can change; follow the current dashboard.
- Prepare the content for its intended frame. Decide whether the program is portrait-only or needs both horizontal and portrait viewers. Keep important subjects, captions, and graphics inside the portrait-safe area if YouTube will adapt a horizontal source.
Add YouTube as a Castr destination
- Add a destination to the Castr stream and choose YouTube.
- Connect the channel. Use the linked-account option, or supply YouTube’s server and stream key if using the manual connection method.
- Complete any platform fields shown in Castr, then toggle the YouTube destination on.
- Verify the destination is enabled and that the stream is reaching YouTube’s Live Control Room before the event.
Choose how to create the vertical feed
YouTube documents two approaches to stream in both horizontal and vertical formats. Set up the vertical format before going live: YouTube says it cannot be added after a stream has started. See YouTube’s vertical live-stream guidance for current controls and eligibility.
Recommended Free Tools
#1 Best Overall
- Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
- Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
- Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
- Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
- 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.
| Approach | Who creates the portrait composition? | Feed setup | Trade-off |
|---|---|---|---|
| YouTube built-in dual stream | YouTube’s Live Control Room layout adapts the source; the default vertical composition is a center crop. | Configure the vertical layout and check its preview. YouTube documents center crop, fit to phone width, and stacked, with zoom and position adjustments. | Simpler when one source can serve both formats, but framing depends on the layout and source composition. |
| Encoder-supplied dual feeds | The production encoder creates the horizontal and portrait feeds. | In Live Control Room, open the Stream tab, select Encoder for the vertical preview, choose RTMP(S), and select the second stream key for the vertical feed. Route each format to its corresponding key through your encoder and Castr destination setup, then go live from YouTube Studio. | More control over portrait framing, but requires a distinct portrait feed and careful stream-key routing. |
Use YouTube’s built-in layout for a single source
When a single Castr source should reach both orientations, configure YouTube’s built-in dual stream and inspect the vertical preview. A center crop can remove content near the sides of a horizontal frame. Try fit to phone width or stacked where available and appropriate, then adjust zoom and position so the subject remains visible. Check the result rather than assuming the automatic layout will suit every shot.
Use encoder-based feeds for a separately composed portrait program
If your encoder outputs independent horizontal and vertical versions, configure both formats in YouTube before the event. Select the vertical preview and second stream key in the Live Control Room, then verify that your encoder and Castr setup route the portrait feed to that key and the horizontal feed to its matching key. Castr’s documented destination workflow does not establish a universal mapping for every encoder or account configuration, so confirm the routing in your actual setup.
Rank #2
- 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
- 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
- Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
- 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
- What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.
Check eligibility and test before the event
- Confirm channel eligibility. YouTube’s vertical live guidance says the channel must be verified and must not have had a live-streaming restriction in the previous 90 days; it also states a minimum age of 16 for live streaming. Check the current YouTube Studio status and rules before scheduling.
- Check portrait framing. Inspect YouTube’s vertical preview, including titles, lower thirds, and any text close to the edges.
- Test the full route. Send a test stream through the same encoder, Castr destination, and YouTube configuration you intend to use. YouTube recommends preparing encoder streams ahead of time, previewing them in Live Control Room, and monitoring audio and video; an unlisted test can help verify the setup (YouTube’s live-streaming tips).
- For mobile streaming, lock screen rotation, check network speed, and test audio and video with an unlisted stream. YouTube says an external battery pack can be useful, but it is optional (YouTube’s mobile live-streaming tips).
Where viewers see vertical live streams—and what differs
YouTube says vertical live streams can appear while viewers browse Shorts and provide a full-screen vertical experience in the YouTube mobile app. Discovery is an opportunity, not a guarantee of distribution. YouTube’s vertical live feed is currently unavailable on tablets, and scheduled live streams and Premieres do not appear in that feed. Check YouTube’s vertical live-stream guidance and its vertical live-feed viewer information for platform changes.
For YouTube dual streams, viewers share a stream URL and chat, but platform features vary by format. YouTube’s feature table lists vertical-feed discovery, scrollable live streams, and certain fan-funding features for vertical; it lists clickable links in chat or the channel description, live pre-roll and mid-roll ads, 4K broadcast bitrate, Premieres, and Live Redirect for horizontal but not the vertical feed. Feature eligibility and availability can change, so check YouTube Studio for your stream. Live Control Room reports metrics for both streams together during and after the stream; metrics for only the vertical stream become available 24 hours later.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Rank #3
- Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
- Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
- Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
- Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
- What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.
Troubleshooting Castr-to-YouTube vertical streams
- YouTube receives video, but the portrait view is wrong: Check YouTube’s vertical preview and layout choice. A center crop may cut off side content; adjust zoom and position or use another documented layout.
- The vertical preview or feed is missing: Confirm that the vertical format was configured before going live. For encoder-based dual streaming, check that the vertical preview is selected and that the second RTMP(S) stream key is used for the portrait feed.
- The wrong format appears on a stream: Verify the encoder output and route each format to its corresponding YouTube key through the Castr setup. Test this routing before the event; do not assume a single destination configuration automatically separates formats.
- YouTube does not receive the Castr feed: Check that the destination is enabled and that the connected account or manually entered server and stream key match the intended YouTube stream.
- Video works but audio or network quality is unreliable: Run an unlisted test, monitor audio and video in Live Control Room, and check the network used by the source device or encoder.
- The vertical stream is not visible to a viewer: Check that the viewer is using the YouTube mobile app and that the stream is not a scheduled stream or Premiere; the vertical live feed is not available on tablets.
Or let it run in the cloud
If your goal is an always-on YouTube channel playing uploaded videos rather than a live camera or a one-off Castr production, StreamNeo is a different option: upload a recording or build a playlist, add your YouTube stream key once, and go live. Nothing has to stay on at home. It streams your upload as made, up to 4K 60fps, at one price per slot; it can recover automatically if YouTube drops the stream. The first day is free with no card. Monthly: $9.99 per month. Start your free StreamNeo day.
Quick Recap
Best Value
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
Rank #4
- Dual Converters, Infinite Potential：Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
- Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
- Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
- Broad Compatible: The usb c to usb adapter widely supports all USB C/ USB A devices like laptops, tablets, cellphones, car chargers, and phone chargers. Such as compatible with MacBook Pro/Air 2023/2022, Thunderbolt 4/3 Devices,Apple MagSafe Watch 9/8/7/SE/Ultra, iPad Pro 2022/2021, Samsung Galaxy S23/S20/S10, and iPhone 17/16/15 Pro. Plug and play
- Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
