What Is Dual Format Streaming?
Dual format streaming means broadcasting horizontal and vertical video simultaneously from a single live session. This can mean sending both orientations to platforms that support dual formats (Twitch, YouTube), or delivering the correct orientation to each destination, such as horizontal to Kick and vertical to Instagram.
This guide covers what it is, why it matters, and how to set it up. It includes the Aitum vertical plugin and other DIY approaches, as well as cloud-based options that work regardless of what device you're streaming from.
What "dual format" actually means
Traditional live streaming produces one format: a 16:9 horizontal video. This worked when gaming and desktop streams dominated. Today, the audiences on TikTok, Instagram, and YouTube Shorts are watching in portrait mode on their phones. A horizontal stream embedded in a vertical feed looks tiny and gets skipped.
Dual format streaming solves this by producing two output formats from a single broadcast:
Horizontal
Full widescreen video for traditional platforms. Ideal for gaming, talk shows, IRL events, and any content that benefits from width.
Vertical
Portrait video for mobile-first platforms. Fills the full screen on phones and competes natively with short-form content.
Important distinction: Some platforms like Twitch and YouTube support both orientations within a single platform: a viewer on mobile can watch a vertical version of your stream. But dual format streaming also covers cross-platform use cases, like streaming horizontally to Kick while simultaneously streaming vertically to Instagram or TikTok. The defining feature is simultaneous output in both orientations from one broadcast.
Why dual format streaming suddenly matters
A few years ago this was a niche concern. Now it's a growth strategy.
Short-form audiences are huge and live
TikTok LIVE and Instagram Live have hundreds of millions of active users who never open Twitch or YouTube. Streaming horizontally only means leaving that entire audience unreachable. Not because your content isn't good, but because the format doesn't fit the screen.
Platforms are pushing vertical-first discovery
Algorithmic discovery on TikTok, Instagram Reels, and YouTube Shorts heavily favors native vertical content. A horizontal video letterboxed into a vertical container signals to the algorithm that the creator is not native to the platform, which suppresses reach.
Twitch and YouTube are adding vertical support
Twitch has rolled out native vertical stream support for mobile viewers. YouTube Live supports portrait-mode streams. Even the established horizontal platforms are adapting, meaning creators now need to think about orientation within a single platform, not just across platforms.
IRL and mobile streaming are vertical by default
Creators streaming from a phone hold it vertically. The content is naturally portrait. Distributing that stream horizontally (letterboxed with black bars) to a Twitch audience looks wrong. Dual format lets mobile streamers hit both audiences with the right format for each.
The core technical challenge
Encoding and delivering two separate video streams from a single live session is harder than it sounds.
Double the encoding load
Producing two separate video streams (one 16:9 and one 9:16) means encoding two outputs simultaneously. On a local machine this doubles the CPU and GPU load. High-end gaming PCs can handle it, but mid-range setups often cannot without quality degradation on both streams.
Double the upload bandwidth
Each stream destination needs its own connection. Two streams to two platforms means roughly double the upload bitrate. A home connection supporting one good-quality stream at 6 Mbps struggles to sustain two at acceptable quality. This is especially painful on mobile connections.
Crop and layout decisions are permanent
The vertical crop of a horizontal stream needs to be chosen at setup time. If your camera framing changes mid-stream, the vertical crop may cut off important content. Designing a scene layout that works in both orientations simultaneously requires planning.
Mobile streams have no dual-format option by default
If you're streaming from a phone, you can only send one orientation from the device. Getting a horizontal crop of a vertical mobile stream, to distribute to Twitch or Kick, typically requires a cloud layer to perform the crop automatically. There is no local plugin for this.
Current solutions for simultaneous vertical and horizontal streaming
There are several ways to achieve dual format streaming today. Each has real trade-offs.
Aitum Vertical plugin for OBS
The Aitum Vertical plugin adds a second output to OBS Studio configured for 9:16 vertical streaming. You design a separate vertical scene in OBS that crops and rearranges elements from your main horizontal layout. Both outputs stream simultaneously: one to your horizontal destination (Twitch, Kick) and one to your vertical destination (TikTok, Instagram).
Aitum Vertical is the most-searched solution for this problem because it's free, works with the software most desktop streamers already use, and is well-documented by the community. If you're streaming from a desktop with OBS and have a capable machine plus sufficient upload, it's a solid starting point.
Strengths
- Free and open source
- Works within OBS, no new software to learn
- Large community with tutorials
Limitations
- OBS-only, no other desktop software
- High local CPU/GPU usage
- Requires double the upload bandwidth
- Doesn't work for mobile streamers
Two streaming devices (one horizontal, one vertical)
The simplest conceptual approach: one device handles the horizontal stream (a PC running OBS to Twitch or Kick) and a separate device handles the vertical stream (a phone running Streamlabs Mobile or IRL Pro to TikTok or Instagram). Each device manages its own upload, account, and destination independently.
Strengths
- No plugins or extra configuration
- Each device optimized for its format
- Failure of one doesn't affect the other
Limitations
- Requires two separate devices
- Two streams are not synchronized
- Managing two separate setups mid-stream is complex
Cloud-based dual format like Streamrun
A cloud relay accepts your single incoming stream from any desktop software or mobile app and handles the transcoding, cropping, and distribution of both formats server-side. Your device sends one stream. The relay delivers horizontal and vertical to each destination. This removes the local CPU and bandwidth constraints of the plugin-based approaches. Desktop streamers can use DualHD resolutions to embed both crops in a single upload. Mobile streamers get automatic format conversion without any local setup. Streamrun is one service that supports this approach.
Strengths
- Works with any software or device
- No extra local CPU/GPU load
- Single upload from your device
- Viable for mobile-only setups
Limitations
- Requires a paid subscription
- Adds a cloud hop to your stream path
Side-by-side comparison
When dual format streaming is worth it
Dual format isn't a requirement for every streamer. Here's how to think about whether it makes sense for your setup.
Good candidates for dual format
- •Twitch and YouTube creators wanting to get discovered on both orientations
- •Creators already multistreaming to Twitch and YouTube who want to add TikTok or Instagram
- •IRL streamers who want to reach a mobile audience on a vertical platform without changing their setup
- •Gaming streamers who primarily face-cam or have content that crops well to vertical
- •Creators building an audience across both long-form and short-form platforms simultaneously
- •Talk show or podcast-style streams where the speaker framing works in both orientations
Less ideal for dual format
- •Games with wide UI elements that get cut off in a 9:16 crop (minimap, inventory bars)
- •Streamers with weak upload connections who can't sustain two stream outputs
- •Content where the horizontal and vertical audiences would expect completely different experiences
- •Creators who haven't yet built an audience on one platform. Better to focus before splitting
Layout strategies that work in both orientations
The biggest creative challenge in dual format is designing content that doesn't look wrong in either crop.
Center-weighted compositions
Keep the most important content (your face cam, the action, the speaker) in the center of the frame. A vertical crop takes the center column of a horizontal frame. If your subject is centered, the vertical crop works without redesigning the scene. This is the lowest-effort approach and works well for face-cam content, IRL streams, and panel discussions.
Dedicated vertical scene layouts
Tools like Aitum Vertical let you design a separate vertical scene in OBS that arranges elements differently for the 9:16 format. Your horizontal scene might have the game full-screen with a face-cam overlay in the corner. The vertical scene could be the face-cam stacked on top of a vertical game crop. More work to set up, but produces a better result for gaming content.
DualHD canvas containing both orientations
DualHD is a resolution format that embeds both horizontal and vertical crops side-by-side in a single widescreen video frame. You send one stream to a cloud relay that extracts both crops and delivers the correct format to each destination. This removes the dual-output complexity on your end entirely. Your software sees a single standard output. Read more at DualHD.org
Recommended workflow approaches by streamer type
The best way to stream vertical and horizontal simultaneously depends on your current setup.
Desktop streamer using OBS
Twitch/Kick primary, adding TikTok or Instagram
Aitum Vertical plugin (free, more control)
Install the Aitum Vertical plugin, design a vertical scene, and configure two RTMP outputs in OBS. Good if your PC is powerful and you have upload headroom.
Cloud relay with DualHD encoding
Encode a DualHD frame and send it to a cloud relay that extracts both crops and delivers each to the right destination. No plugin required, works with any encoder, and the dual-format conversion happens server-side.
Mobile streamer (phone only)
IRL streamer wanting both vertical and horizontal platforms
Two devices (vertical + horizontal)
Run a separate horizontal stream from a laptop alongside your vertical phone stream. Gives you full control over each platform independently, but requires managing two setups simultaneously.
Cloud relay with automatic format conversion
Stream from your phone to a cloud relay that auto-generates the vertical crop and distributes both formats. No laptop required. The conversion happens server-side.
Professional setup (not OBS)
Using vMix, Wirecast, or hardware encoders
Native multi-output in vMix or Wirecast
vMix and Wirecast both support multiple simultaneous stream outputs natively. Configure one output for each orientation and target different RTMP ingest endpoints. More setup work, but keeps everything within your existing software.
Cloud relay with format conversion
Send a single RTMP or SRT stream to a cloud platform that handles both format outputs. Works regardless of which software you're using, and offloads the bandwidth and transcoding overhead.
The future of live streaming formats
Orientation is becoming a first-class concern in live streaming infrastructure, not an afterthought.
Platforms will standardize vertical support
Twitch's vertical mode rollout signals where the industry is heading. Within a few years, every major streaming platform will offer native vertical viewing modes, and content creators will be expected to provide both. Dual format won't be a competitive advantage. It'll be table stakes.
Automatic format conversion will become standard
The friction of managing local plugins, bandwidth headroom, and encoding load will push more creators toward cloud-based format conversion over time, following the same pattern that drove cloud multistreaming adoption. Whether that replaces local plugin approaches or simply coexists with them will depend on how well cloud options compete on latency and price.
Mobile-first streaming will grow
Streaming hardware is getting better and more affordable. More creators will stream significant portions of their content from mobile. Tools that treat mobile as a first-class input and generate both formats automatically will have an advantage over desktop-centric plugins.
The format landscape will diversify further
Horizontal and vertical are the current binary, but emerging platforms may push square, ultra-widescreen, or even dynamic aspect ratios. The creators and infrastructure providers who build format-agnostic pipelines now will adapt most easily to whatever comes next.
How Streamrun fits into this
Streamrun is the cloud relay described above. It accepts RTMP and SRT from any desktop software or mobile app, handles the format conversion server-side, and distributes both horizontal and vertical to your chosen platforms simultaneously.
- Desktop streamers can send a DualHD frame from OBS, Streamlabs, vMix, or any other encoder, with no plugin required
- Mobile streamers stream from their phone and Streamrun auto-generates the vertical crop for portrait platforms
- Both formats are delivered to their respective destinations from a single upload: For example, horizontal to Kick, vertical to TikTok and Instagram, and both orientations to Twitch and YouTube
FAQ: dual format and simultaneous vertical and horizontal streaming
What is dual format streaming?
Dual format streaming means producing and distributing horizontal (16:9) and vertical (9:16) video simultaneously from a single live broadcast. The two formats can go to different platforms, for example horizontal to Twitch or Kick and vertical to Instagram or TikTok, or both orientations can go to the same platform if supported (e.g. Twitch, YouTube).
How do I stream vertical and horizontal at the same time?
The most common approaches are: the Aitum Vertical plugin for OBS (which creates a second vertical OBS output), a manual dual OBS scene setup using two stream outputs, or a cloud streaming relay that handles both formats from a single input without any plugin or additional software. Desktop streamers using a cloud relay can use DualHD resolutions to send both formats from one encoder. Mobile streamers get the alternate format automatically generated from their stream by the cloud relay.
Is the Aitum Vertical plugin a good option for dual format streaming?
The Aitum Vertical plugin for OBS is a popular free option for dual format streaming from a desktop. It creates a separate vertical scene and output within OBS, streaming both simultaneously. The main limitations are that it requires OBS-specific configuration, increases local CPU/GPU load, and running two outgoing stream connections from a single PC strains upload bandwidth. It works well on capable machines with good upload headroom.
Can I stream to Kick horizontally and Instagram vertically at the same time?
Yes. This is a common dual format use case. With a cloud platform like Streamrun, you set up a horizontal output to Kick and a vertical output to Instagram simultaneously. Streamrun handles the format conversion and delivery. Without a cloud layer, you need two separate OBS outputs and enough upload bandwidth for both streams.
What resolution should I stream in for dual format?
For full-quality dual format from a desktop, use a DualHD resolution, which is a widescreen format that embeds both horizontal and vertical crops in a single video frame. For mobile streams, a cloud relay can generate the alternate crop automatically from your existing input without any extra configuration. In most cases, Full HD horizontal and 720p vertical are good targets for dual format streaming.
Do Twitch and YouTube support vertical streaming?
Twitch and YouTube have added native dual format streaming support to help mobile viewers discovering content. TikTok and Instagram are natively vertical, Kick supports horizontal streaming. The practical reality is that most creators targeting short-form audiences distribute vertical to TikTok or Instagram and horizontal to Twitch, Kick, or YouTube simultaneously.
What are the best vertical streaming plugin alternatives to Aitum?
Aitum Vertical is the most widely used OBS plugin for vertical streaming. Other approaches include running two separate devices (one per orientation), manual multi-output configuration in vMix or Wirecast, or cloud-based relay services like Streamrun that handle format conversion server-side and remove the need for any local plugin or extra device.
Stream horizontal and vertical simultaneously
One stream in. Both formats out. To every platform. Streamrun handles the rest.