# Portrait digital signage: hanging the TV sideways, and telling ChannelOS which way you turned it

> There is no portrait switch in ChannelOS, on purpose. You pick one of four quarter turns, because a two-state toggle cannot say which way the set was turned, and 90 against 270 is the difference between a readable board and an upside-down one.

Source: https://channelos.tv/blog/portrait-digital-signage-tv
Published: 2026-08-13
Category: How-to
Author: The ChannelOS team

**ChannelOS has no portrait or landscape toggle for a screen. Under Screens, either while pairing or on a screen's Device card, there is a section called How it is mounted with four choices: Upright, Turned left, Upside down, Turned right. You pick the one that matches how the set is physically hung, and portrait or landscape is worked out from that and shown read-only on the screen's card. Turned left means the TV's top edge is on the left; Turned right means it is on the right. Those two look identical on a desk and opposite on a wall, which is why a two-state toggle was rejected: it cannot say which way the set was turned. A show's shape is a separate setting, chosen at New show under Shape, and the two meet only at render: a portrait show fills a quarter-turned 1920x1080 panel edge to edge, while on an upright one it plays as a column about 31.6% of the width with bars at the sides. Nothing is cropped and nothing is stretched.**

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The only wall left in the shop is the narrow one beside the door. So the TV went up on its side this week, the bracket held, and then the board came on lying flat: headings running up the wall, prices reading bottom to top, the whole thing unreadable from two feet away.

That is not a mounting problem. The set is hung correctly. The software just does not know it yet, and telling it is one control in one place.

## Where do I tell ChannelOS the TV is sideways?

Go to **Screens**. Either pair a new screen, or open one you already have and use the **Device** card. Both paths land on the same section, headed **"How it is mounted"**, and on the screen's detail page it carries one helper line that is the entire rule:

> Turn this to match the TV, not the content.

Under that are four buttons, not a switch:

| What you pick | Its tooltip | Where the TV's top edge is now |
|---|---|---|
| **Upright** | The TV is the normal way up | Up, where it normally is |
| **Turned left** | The top of the TV is on the left | On the left |
| **Upside down** | The TV is hung the other way up | Down |
| **Turned right** | The top of the TV is on the right | On the right |

Pick one and the picture turns to sit the right way up. Portrait or landscape is then **worked out for you** and shown read-only as a badge on the screen's card. You never set it, because it is not a fact about your wall. It is a consequence of one.

## Why four buttons instead of a portrait toggle?

A portrait and landscape switch is the obvious control to build here. We deliberately did not build one.

**A two-state toggle cannot say which way the set was turned.** Both quarter turns are portrait. Turn a TV clockwise and its top edge ends up on the right; turn it anti-clockwise and the top edge ends up on the left. A toggle set to "portrait" has to pick one of those on your behalf, and half the time it picks the wrong one. What you get then is a board that is the correct shape and completely upside down, which is worse than landscape because it looks like the software worked.

That is not hypothetical, and we are not pretending we are innocent of it. If you paired the screen by asking the AI concierge for a portrait screen rather than by using the picker, it answered with a shape rather than a turn, and a shape answer is stored as Turned left every time. If your board came up upside down after a pairing like that, this is why, and the fix is the same one click below.

So the mount is four quarter turns, portrait and landscape are derived from the mount, and the derived value is shown but never edited. One fact, stored once, displayed twice.

## Which of the four is mine?

Here is the part worth reading twice, because it is where people get it backwards.

The stored turn is the **cancelling** turn: how far the player has to rotate its own output, clockwise, for the picture to sit upright on a panel that was hung sideways. **Turned left** stores 90, and 90 means the panel itself was turned **anti-clockwise**, so its top edge is now on the **left**. **Turned right** stores 270, the panel was turned clockwise, top edge on the right. The player then turns its output the other way by the same amount and the two cancel out.

You do not have to hold any of that in your head. There is a physical test you can run standing in front of the set, with no phone in your hand:

1. Find the TV's **top edge**. It is the one that would be up if the set were hanging normally: usually the edge opposite the feet, and on most sets the one without the brand name on it.
2. Look at which side of the wall it is on **now**.
3. Top edge on the left is **Turned left**. Top edge on the right is **Turned right**.

That is the whole rule. It is stated in the labels themselves, which is why the tooltips read "The top of the TV is on the left" rather than anything about degrees.

There is an end-to-end test whose only job is to fail if those two labels are ever swapped back. It exists because swapping them is the single easiest mistake to make in this part of the product, and because it is invisible in every place except a wall.

## The board is sideways. What did I get wrong?

Almost certainly Turned left against Turned right. Those two are the mistake, and they are the mistake because they look identical on a laptop and opposite on a wall. Nothing you can see in the dashboard distinguishes them until the picture is on the glass.

Run the test above, change the setting on the screen, and the TV turns immediately. The corrected mount is pushed live to the player, so there is nothing to republish, no page to reload, and nobody has to walk over to the television or find the remote. If you are up a ladder with the set in your hands, someone at the counter can fix it on their phone while you hold it.

Two smaller things worth knowing while you are in there. Only the four quarter turns are accepted, so a value like 45 is refused outright and the TV keeps the mount it already had rather than half turning into something nobody chose. And the operator preview on your dashboard shows the **show's** shape, not the panel's turn. The wall is the check.

## Is the show's shape the same setting?

No, and this is the second thing people conflate. They are separate, they live in different places, and they mean different things.

- **The screen's mount** says how the physical panel is hung. Screens, then How it is mounted.
- **The show's shape** is the canvas the slides were composed on. It is chosen at **New show** under **Shape**, as Landscape or Portrait, and it is changeable later in the editor.

They meet at render: the mount decides the frame the player draws into, and the show's shape decides what sits inside that frame. One other place mentions both, and only to warn you. When you publish a show to a screen, the dialog lists the shape-matched screens first and marks the rest with where the bars will land. That mark is advisory. Nothing in the product blocks a mismatch, and nothing changes the show because of one.

## What happens when the shapes do not match?

It still plays. Here is the arithmetic on an ordinary 1920x1080 panel, which you can check against your own wall:

| Mount | Show shape | Frame the player draws into | Board size on screen | What you see |
|---|---|---|---|---|
| Upright | Landscape 16:9 | 1920x1080 | 1920x1080 | Edge to edge |
| Upright | Portrait 9:16 | 1920x1080 | **608x1080** | A column using about **31.6%** of the width, bars at the sides |
| Turned left or right | Portrait 9:16 | **1080x1920** | 1080x1920 | Edge to edge, the whole panel |
| Turned left or right | Landscape 16:9 | **1080x1920** | 1080x608 | Bars top and bottom |
| Upside down | Either | 1920x1080 | Same as Upright | Same bars, picture flipped |

The picker says the same thing in one sentence under the four buttons, updating as you click: it tells you which shape plays edge to edge on this mount, and where the bars land for a show of the other shape.

Read the table the right way round. **Nothing is cropped and nothing is stretched.** A mismatch costs you screen area, not the board. A landscape menu on a portrait panel is a smaller, correct menu with black above and below it, not a squashed one with the prices cut off. That is a deliberate trade: the alternative is software deciding which third of your board to throw away.

## Should you hang the TV sideways at all?

Sometimes no. Two honest reasons not to.

**If the only reason is that portrait looks modern, skip it.** On an upright panel a portrait show gives up about two thirds of the glass to black bars, and on a turned panel every landscape show you already own does the same in the other direction. Turn the set because the wall is narrow, because the content is a list read top to bottom, or because it sits in a window facing a footpath. Not for the look.

**If you need one deck to fill both a portrait and a landscape screen automatically, this is not the product for that.** ChannelOS does not swap in a shape-matched variant per screen. One show is authored in one shape, and every screen airing it gets that shape letterboxed into whatever frame its mount produces. If you are running a mixed fleet where every board must fill every panel, either author the portrait boards separately or buy a platform built around per-screen layout variants.

And the hardware caveat, placed here rather than hidden at the bottom: **portrait is one of the few cases where a commercial display can earn its price over the consumer TV you already own.** The others are a 16 to 24 hour duty cycle and direct sun. Whether a given set supports portrait mounting is a question for that model's own manual, and we are not going to answer it for a TV we have not seen, so read it before you drill. The rest of that decision, including why to avoid OLED for a board that holds the same layout for hours, is in [how to turn the TV you already own into a sign](/blog/how-to-turn-your-tv-into-digital-signage).

## What actually does the turning

The player does, in the browser, as a transform on the page. It reads the mount from your account and never from the device, and that is on purpose: **a TV hung sideways still reports 1920x1080**, and the browser event that fires when you rotate a phone never fires for a wall bracket. A player that guessed from the hardware would guess wrong on every screen this post is about.

Which also means there is nothing to install. Open `play.channelos.tv` in the browser the TV already has, [pair it with the six-character code](/blog/create-show-schedule-channel-pair-screen), and set the mount from your phone. There is an Android TV app, it is in closed testing, and its store page does not resolve today, so we are not going to point you at a link that 404s. The board is identical either way, and the app does not do the rotating: the player does. If the browser in your set is too old to render a board properly, that is a different question and it is answered in [do you need a signage player](/blog/digital-signage-player-do-you-need-one).

The first screen is free. After that it is 499 rupees per screen per month, or 399 per screen per month paid yearly, which is 4,788 a year. [Pricing](/pricing) has the rest, and [channels](/blog/manage-many-screens-with-channels) covers what happens when the second and third screens go up.

## Get the mount right in the first minute

Hang the set, open the player on it, pair it, then pick the button that matches the top edge you can see. If the board comes up sideways, it is the other one of the two, and fixing it is one click that reaches the TV before you have put your phone down.

So decide the wall today rather than the software. **Get a screen live, free**: open `play.channelos.tv` on the set that is already in the room, pair it, and pick the mount. If the answer to "which way did I turn it" is still unclear when you are up there, the short version lives with the [other screen questions we get asked](/answers).

## Frequently asked questions

### Why four mount options instead of a portrait and landscape toggle?

Because a two-state toggle cannot say which way the TV was turned, and turning a set clockwise against anti-clockwise is the difference between a readable board and an upside-down one. Both are portrait. Four quarter turns can say which one you did; a toggle has to guess, and half its guesses are wrong.

### Is the show's shape the same setting as the screen's mount?

No. They live in different places and mean different things. The screen's mount says how the physical panel is hung. The show's shape is the canvas the slides were composed on, chosen at New show under Shape and changeable later in the editor. They meet at render, when the mount decides the frame and the show's shape decides what sits inside it. One other place mentions both, and only to warn you: publishing a show to a screen lists the shape-matched screens first and marks the rest with where the bars will land. That mark is advisory and nothing blocks a mismatch.

### Does the Android TV app do the rotating?

No. The turning is done by the web player as a transform on the page, so it is the same in the TV's own browser as it is inside the app. The app is in closed testing and its store page does not resolve today, which is why this post points you at play.channelos.tv instead.