Twitch Dual Format streaming lets you offer a portrait layout to phone viewers while keeping a conventional landscape broadcast for desktop and television viewers. Twitch began rolling the feature out to all streamers on June 17, 2026. Its 1440p streaming upgrade was a separate rollout for Affiliates and Partners, so adding a vertical layout does not require turning your broadcast into a higher-resolution production.
The useful approach is to build a second composition around the same content, not squeeze your finished desktop scene into a narrow rectangle. Preserve the working landscape layout, arrange the portrait version separately, and test both together. One particularly easy mistake deserves attention: cropping a shared source with the wrong OBS control can change its appearance everywhere, including your desktop broadcast.
Preserve the working setup before adding another canvas
Before installing plugins or rearranging sources, export your OBS scene collection and save your existing streaming configuration. OBS provides scene-collection export and import specifically to preserve and transfer scenes and their sources. Keep an untouched backup rather than relying on memory to rebuild a layout.
Treat this as a controlled change to your existing OBS setup and source organization, not a reason to replace every scene at once. Give the experimental collection an obvious name and note which plugins it needs. Avoid changing your encoder, camera settings, overlays, and broadcast resolution during the same test.
For the workflow below, use OBS Studio 32.0.0 or newer with a current compatible Aitum Vertical build. Get the plugin from the official Aitum Vertical releases, rather than an old tutorial’s mirrored installer. Aitum adds another canvas to OBS and supports linking its scenes with your normal scenes.
Leave your established landscape composition alone during the first pass. Start with a small portrait scene set: gameplay, conversation, and a break screen. The aim is to establish a reliable workflow before spending time on animated borders or elaborate transitions.
Connect the vertical canvas to Twitch
In Twitch’s Dual Format setup guide, the OBS workflow connects the additional canvas through Enhanced Broadcasting. Under Settings → Stream, connect your Twitch account, enable Enhanced Broadcasting in the Multitrack Video section, and set Additional Canvas to Aitum Vertical. Restart OBS if the canvas option does not appear after installation.
Build the portrait scene at 1080 × 1920. Add your existing gameplay, camera, and other required sources to the vertical composition, then arrange them for that frame. To synchronize switching, right-click a vertical scene in the Vertical Scenes dock, choose Linked Scenes, and select its corresponding horizontal scene. Switch from the main horizontal scene list during the broadcast.
Link the break and ending scenes as carefully as the gameplay scene. During rehearsal, switch to your break screen and confirm that neither orientation still shows the camera, desktop, or anything you intended to hide. A successful gameplay transition is not enough to validate the whole scene set.
When ready for a test broadcast, use OBS’s main Start Streaming button. Twitch says the separate green Go Live button in the vertical dock is not required for this workflow.
Crop the scene item, not the shared source
Reusing a camera or game capture does not mean every adjustment stays local to the layout you are editing.
The distinction is explained in OBS’s Crop/Pad documentation: a Crop/Pad filter changes the underlying source and applies to every instance of that source across scenes. Cropping through the Transform controls works differently. For a portrait-only framing adjustment, use the scene item’s transform rather than applying a Crop/Pad filter to the shared source.
Consider a hypothetical webcam layout. On desktop, you want a wide shot that includes your hands and controller. On mobile, you want a tighter view of your face. A source-level crop can remove the surrounding image from both layouts. A crop applied to the portrait scene item lets you make that composition tighter without making the same framing change to the landscape scene.
OBS exposes these positioning and sizing controls through Transform → Edit Transform. Use that window for deliberate adjustments instead of dragging until the preview happens to look right.
After changing a shared source, inspect both canvases. Make this a habit with camera adjustments, capture properties, and filters—not just cropping. The desktop view should remain an actively checked output, rather than something you assume is unchanged because you were editing the portrait preview.
Design around what viewers need to understand
A centered crop can look attractive while removing information that explains the game.
The geometry shows how much is at stake. If a 16:9 image is cropped to a full-height 9:16 view without stretching, the remaining width is only 31.6% of the original. That is a calculation from the two aspect ratios, not a performance measurement. More than two-thirds of the original horizontal field falls outside the portrait frame.
That may be acceptable for a close-up reaction shot. It is a poor default for a game whose health indicators, map, objectives, or inventory sit near the edges.
The alternative is to retain the complete game image within the portrait composition. At 1,080 pixels wide, a 16:9 image is approximately 608 pixels tall. This leaves space for a separate camera view or supporting information, but it also makes small game text smaller. Neither filling the screen nor preserving the whole image automatically solves readability.
Use the content to choose the starting layout:
| Broadcast content | Suggested portrait arrangement | What to check on a phone |
|---|---|---|
| Conversation or reactions | A large camera view with restrained supporting graphics | Facial expressions and any captions remain unobstructed |
| Gameplay with important corner information | The complete game frame with a separate camera area | Health, map, timers, and objectives are readable |
| Tutorials or menu navigation | A full-interface overview, with a deliberate close-up when explaining a detail | Viewers can follow the cursor and identify the setting being changed |
These are design starting points, not tested presets. A layout that works for one game may fail when you open an inventory, enter a scoreboard, or switch to a different title.
Twitch overlays chat and controls on the mobile portrait view. Keep essential information within its safe-zone guidance and omit a second baked-in chat overlay from the vertical canvas.
Judge the result on an actual phone at normal viewing distance. Ask someone to identify the current objective, read an important number, and explain what just happened without rotating the device. Their difficulty is more useful feedback than whether the composition looks impressive on your editing monitor.
Account for more than two video outputs
Two visible layouts do not necessarily mean your computer is producing only two encoded video versions.
Enhanced Broadcasting can generate multiple quality levels in your broadcasting software. These give viewers alternatives when their connection or device cannot comfortably handle the highest-quality stream. Twitch also provides additional server-side transcoding support to eligible channels, reducing how much of that work must happen locally. Enhanced Broadcasting remains required for Dual Format even when that support is available.
Do not assume another creator’s settings will impose the same load on your machine. Their channel may have different server-side support, and their broadcast may use different sources, recording settings, or quality levels.
Twitch describes Maximum Streaming Bandwidth and Maximum Video Tracks as resource limits, not quality targets. Raising either value simply to make it “better” misses their purpose. Establish a working baseline, observe the actual resource use, and adjust only in response to a specific problem.
When the broadcast stutters, separate local processing trouble from connection trouble. OBS’s performance troubleshooting guide explains why a game can appear smooth while OBS struggles: the game may be consuming GPU capacity that OBS also needs. Suggested remedies include limiting game frame rate and reducing demanding graphics settings or expensive sources.
Network-dropped frames are a different problem. OBS associates them with an unstable connection to the streaming server or an inability to sustain the configured bitrate. Reducing decorative overlays will not repair a congested upload route; investigate connection stability and the total outgoing data instead.
For the first comparison, keep the game, scene, and other settings consistent. Test your established horizontal broadcast, then add the portrait layout. This will not produce a laboratory benchmark, but it gives you a clearer basis for deciding which change introduced the problem.
Rehearse the whole broadcast, not just the opening scene
A useful rehearsal should include the moments most likely to expose layout mistakes: opening a menu, triggering an alert, switching to conversation, taking a break, and returning to gameplay.
Watch the landscape output on a computer and the portrait output in the mobile app. Check the same moment in both. Do not judge the portrait version only from the OBS preview, where the viewing size and surrounding interface differ from the audience’s experience.
Listen as well as look. Check microphone clarity, game balance, alert volume, and lip synchronization. Mute unnecessary monitoring devices so playback from one screen does not create an echo that you mistake for a routing fault.
Afterward, review the replay and a sample clip. Look for explanations that lost their context, captions that became difficult to read, and transitions that left one orientation on the wrong scene. Keep a short record of the specific failures so the next test changes only what needs fixing.
The release decision should be practical: can someone understand the broadcast comfortably in either orientation, and does the added layout leave the established stream reliable? A simpler portrait composition that passes those tests is a better starting point than a full-screen crop that hides the game or a complex scene that makes both versions stutter.