Dual-Format Livestreaming: How to Stream Vertical and Horizontal at Once in 2026

Last updated: October 2026

A vlog audience now lives in two shapes at once: the wide screen on the desk or TV, and the tall phone screen people scroll in bed. Dual-format livestreaming ends the choice between them. One broadcast goes out in 16:9 and 9:16 at the same time, under one link, with one shared chat. This guide covers the three ways to run it, the framing that keeps both versions watchable, and the numbers that tell you whether the second shape earned its keep.

Two shapes, one broadcast: what dual-format streaming is

The important word is single. This is not two broadcasts running side by side. YouTube treats the pair as one event: subscribers get one go live notification, the replay lives at one address, and the chat scrolls as one conversation both audiences read and write in.

The vertical half exists for one reason: discovery. A vertical live stream can surface inside the Shorts feed, where a phone viewer can tap in, watch full screen, and keep swiping to more live streams. The horizontal half keeps everything a normal stream has always had, including features the vertical feed lacks, spelled out in the table ahead.

Three production routes lead to the same broadcast: YouTube generates the vertical version from your horizontal feed, you send YouTube a vertical feed of your own from an encoder such as OBS, or a multistream service carries both shapes for you. They differ in how much control you get over the portrait picture, and how much of the work and bandwidth lands on your desk.

Why stream in both formats at once

The session also ends as one video at one URL, so its watch time collects in one place. Our vertical video guide covers how the tall format behaves across Shorts and uploads; this article stays on the live version of the same idea.

Before any route works: eligibility and the ground rules

Dual format changes none of those standing rules, and the waiting period cannot be fixed an hour before showtime, so enable live early. Our complete guide to livestreaming on YouTube covers enabling live and the Live Control Room; this article builds the second format on top of that ground.

One ground rule shapes everything that follows: the two-format decision is made before you go live, since the vertical format cannot be added once a stream has started. And know which feed carries which features, because they are not twins:

Read the table as a division of labour, not a list of defects: the vertical feed is a discovery surface with fan funding attached, the horizontal feed the full commercial surface, and a dual stream runs both at once.

Route one: let YouTube build the vertical version

A plain center crop is a blunt instrument, so YouTube gives you a layout editor for the vertical side. In YouTube Studio, open the scheduled stream from the Manage tab of the Live Control Room and choose Edit layout on the vertical preview. The canvas offers three arrangements: Center crop, the middle strip of the wide picture; Fit to phone width, the whole frame scaled down; and Stacked, two parts of the scene piled one above the other, handy when two people sit side by side. Zoom and position adjust on the crop, and a layout set this way can keep being adjusted while the stream is live. The trade is control: YouTube reframes your picture rather than redesigning it, so wide frame graphics and edge text can come out cramped in portrait.

To stream wide only, the same panel turns the feature off: Stream tab, Stream settings, switch off Dual stream. Decide before the stream starts, because the vertical format cannot be added once you are live.

Route two: send your own vertical feed from OBS

OBS Studio on its own has one canvas, so the second output comes from a plugin. The usual tool is Aitum Vertical, a free third party plugin listed in the official OBS resources library; it is not part of OBS itself. It adds a vertical canvas, 1080 by 1920, with its own scenes and sources docks, so you build a real portrait layout: the same camera reframed tighter, text set larger, overlays arranged for a phone. Vertical scenes can link to your main scenes so scene changes carry across both outputs, and the vertical canvas has its own streaming settings, where the second key goes.

YouTube’s own warning for this route deserves repeating: check that the vertical and horizontal content match, and that the correct format goes to the corresponding stream key. Two outputs and two keys invite the classic accident, portrait video on the horizontal key and wide video on the vertical one, which is why the test routine below exists.

The encoder route also moves the whole bill onto your machine and your connection: OBS composes and encodes two pictures at once, and your upload carries both bitrates, added up properly in the bandwidth section below. The payoff is a vertical feed that looks made, not derived. A camera giving the encoder a clean, sharp picture helps here too, and our streaming cameras guide covers the models vloggers stream with.

Route three: a multistream service carries both shapes

The shape varies by service. Some work through a plugin inside OBS that builds the vertical layout much like the Aitum route, then route both outputs through the service. Others accept one horizontal feed and produce the portrait version on their servers. With a service that produces the portrait version on its own servers, the heavy second encode can leave your desk; with a plugin variant, your machine still builds the vertical layout, and the service’s dashboard becomes where both chats are watched together. What a service includes at which level changes often, so check its own pages before building a workflow around it.

Frame one scene so both crops survive it

Start with the subject. A vlogger sitting dead center, the natural talking head position, is already dual-format friendly. Trouble starts with wide framing habits: two chairs side by side, a guest at the edge, action travelling across a workbench. For two people, pull both chairs toward the middle and accept a cosier wide shot, use the Stacked layout on the Auto route, or build the encoder route’s vertical scene with one person above the other.

Graphics need the same discipline. Names, lower thirds, product titles and on screen prompts should live inside the center band on a shared scene; anything parked in a corner of the wide frame sits outside the portrait crop entirely. On a dedicated vertical canvas, rebuild the graphics for the phone: text noticeably larger than feels natural on your monitor, and clear of the very top and bottom, where the app’s own interface sits.

The bandwidth bill: what two feeds actually cost

Work it out from YouTube’s recommended live bitrates, not folklore. For H.264, YouTube recommends 14 Mbps for 1080p at 30 frames per second, 17 Mbps at 60, and for H.265 or AV1, 10 Mbps at 1080p30. A vertical 1080 by 1920 feed at 30 frames per second is the same class of picture, so cost it the same way:

The last column is the total divided to leave that 20 percent spare, rounded up. It is arithmetic, not a promise: speed test the connection you will actually stream from, at the time of day you will stream, before trusting any row. The encoder settings deserve the same care: YouTube asks for constant bitrate encoding and a keyframe every 2 seconds, never longer than 4, on both feeds, and recommends RTMPS, the encrypted form of RTMP, wherever the encoder offers it.

Latency is chosen once, for both audiences together. Normal gives the best picture and least buffering, and supports every resolution and feature on the horizontal feed. Low brings most viewers under 10 seconds of delay, ultra low under 5, suiting a chat heavy show, but both drop 4K and ultra low raises the buffering risk. Pick by how much you talk with chat, then leave it alone.

One chat and one moderation pass for two audiences

Hosting two audiences in one room changes the rhythm. Vertical viewers arrive cold, mid-stream, from a feed scroll, having never heard your introduction. A short recap every so often brings them in without boring the regulars, and saying each question out loud before answering it helps anyone who just landed.

One asymmetry needs planning around: clickable links do not work on the vertical feed, in chat or in the channel description, so if your stream points people somewhere, the phone audience cannot tap it. Read short addresses out loud, keep the full link where horizontal viewers can click it, and do not judge a call to action by vertical clicks that were never available. Fan funding has no such gap: Super Chat, Super Stickers, memberships and gifts all work there.

Test both formats before anyone is watching

YouTube’s own guidance is to test with audio and movement similar to the real event, and to monitor stream health during the broadcast. A dual rehearsal adds the second picture: wave your arms at the edges of the frame, walk to where a guest will sit, hold up the product you will show, then check the vertical preview to see what the crop did with it all, while you are the only viewer.

On the encoder route, one check saves public embarrassment. Start the horizontal output alone and confirm it lands on the horizontal preview; then start the vertical output alone and confirm a portrait picture lands on the vertical preview. Sending the wide feed to the vertical key is the most common dual setup mistake, and it is invisible from inside OBS, where both outputs look perfect on their own canvases.

Finish by watching the vertical feed in the YouTube app on your phone, as a Shorts viewer will meet it, and run the setup long enough for dropped frames or a struggling encoder to show themselves. Put the real slot on the calendar after the rehearsal; the slot deserves the same audience logic you would give an upload, and our best time to post on YouTube guide works through that method for regular videos. Once scheduled, edit its vertical layout before you go live.

After the stream: reading two audiences in the numbers

Combined numbers tell you the broadcast worked, not which half carried it: a stream that felt quiet might have been found by hundreds of phone viewers who watched briefly and moved on. Wait for the vertical only figures, then compare like with like: watch time per format, chat messages overall, and subscribers gained, against your recent single format streams. One caveat belongs in every such review: YouTube does not document how the Shorts feed weighs a dual stream’s vertical half against a dedicated vertical only stream, so your own figures are the only evidence going.

When one format is the better call

Some pictures do not crop: a slide deck with small text, a wide two person interview that cannot be restaged, a demonstration travelling across a workbench. Forcing those through a center crop gives phone viewers a worse stream than no vertical stream at all, and Premieres sit outside the system entirely. Bandwidth draws the other hard line: the encoder route at full quality wants roughly 35 Mbps of real upload, and if your connection offers half of that, one stable horizontal stream beats two starving feeds dropping frames in turns. The Auto route is the middle path, asking nothing extra of your connection.

Hold it this way: leave the Auto layout on unless your content fights the crop, and treat the encoder route as a deliberate upgrade for when the vertical audience has shown up in your numbers and earned the extra work.

Frequently asked questions

Keep exploring

• How to Livestream on YouTube
• Vertical Video Guide for Vloggers
• Best Cameras for Streaming
• YouTube Analytics for Vloggers