Automatic content recognition: your smart TV is watching back

Many smart TVs can tell what is on their own screen. The feature is called automatic content recognition, or ACR, and it works a lot like the music apps that name a song playing in a bar. The TV samples the picture or the sound every fraction of a second, turns the sample into a fingerprint and checks it against a database on a server. It does that with the local news over an antenna, with a movie from a Blu-ray player and, as researchers found in 2024, with a laptop plugged in over HDMI.

You probably agreed to it during setup, somewhere between the Wi-Fi password and the channel scan. That is annoying, but it is fixable. The same 2024 study checked whether the off switch does anything, and on the two brands it tested, it did. More on that below, after a look at what the TV is actually sending and where that data has ended up.

How automatic content recognition works

Nothing gets recorded in the sense of a video file. The TV picks out a few pixels or a slice of audio, reduces them to a short signature and sends the signature to a server. On the other end sits a library of signatures from shows, movies and ads. A match tells the platform what is playing, down to the second.

Amazon explains this fairly plainly in its help pages for Fire TV smart TVs. The fingerprint is built from encoded audio or pixel samples, and fingerprints that match nothing in the database are thrown away, so your home videos stay unrecognized. Samsung says on its US support page that it does not record or watch the content on your screen. What it does collect, according to the same page, is your viewing history with programs and time spent, TV identifiers and your IP address.

How often the TV looks depends on the brand. A 2024 study cites the makers’ own documentation: Samsung captures a frame every 500 milliseconds, LG every 10 milliseconds. The fingerprints are batched before they leave the house. The researchers saw LG talk to its ACR servers roughly every 15 seconds and Samsung about once a minute. LG now says its ACR fingerprints audio and takes no screenshots.

A TV sees everything it displays, whether it comes from an antenna, a cable box or a console. A streaming service only knows its own app, while the TV also catches the commercials in the broadcast schedule. That is why ad companies care.

What researchers measured in California and London

For years, most of what people knew about ACR came from privacy policies and guesswork. In fall 2024 a team from UC Davis, University College London and Universidad Carlos III de Madrid presented a measurement study at the Internet Measurement Conference, an academic venue for network research. Led by Gianluca Anselmi and Yash Vekaria, the group set up LG and Samsung TVs in California and in the UK and captured their network traffic.

They ran the TVs through ordinary situations: an antenna channel, the manufacturer’s own free channels, Netflix and YouTube, a laptop or console over HDMI, screen casting from a phone, and the home screen doing nothing. Each situation was repeated with and without a TV account and with and without consent to advertising and tracking.

HDMI is the result that tends to surprise people. If you use the TV as a big monitor for a laptop or a game console, you would not expect it to report anything. Netflix and YouTube, on the other hand, stayed quiet. The authors suspect the big streaming services do not want their content fingerprinted, and a source they cite says as much for Netflix.

The useful finding sits in the second to last row. Once the team declined every advertising and tracking option, including the viewing information agreements, traffic to the ACR servers stopped entirely, in both countries and on both brands. The study did not test which single switch does it. Being signed in made no difference. ACR ran without an account just as well. Two brands in two countries is not the last word, but it is the most careful independent look anyone has published.

Vizio and a setting called Smart Interactivity

The case that put ACR on the map was Vizio. In February 2017 the Federal Trade Commission and the New Jersey Attorney General’s office announced a settlement with the company. According to their complaint, starting in February 2014, Vizio TVs captured second-by-second information about what was on screen, from cable, broadband, set-top boxes, DVD players, over-the-air broadcasts and streaming devices. The agencies put the number of affected TVs at 11 million.

The tracking sat behind a setting called “Smart Interactivity,” which Vizio described as enabling program offers and suggestions. The complaint says Vizio sold the data to third parties, who used it to target ads across devices, and that Vizio helped attach demographic details such as sex, age, income, marital status, household size, education and home ownership.

Vizio paid $2.2 million and agreed to clearly disclose its data collection and get affirmative express consent first. The FTC’s business blog asked whether a name like Smart Interactivity would tell anyone that everything they watch was being collected and shared. Its answer was short: “We don’t think so.”

Texas sues five TV makers

The most recent round started on December 15, 2025, when Texas Attorney General Ken Paxton filed lawsuits against Sony, Samsung, LG, Hisense and TCL. The state alleges that the companies used ACR to collect what Texans watch without proper notice or consent. The press release claims the software can capture screenshots every 500 milliseconds. Those are allegations made by the state, not findings by a court.

Two of the cases have ended in agreements so far. In February 2026 Samsung agreed to stop collecting or processing ACR data from Texas consumers without express consent and to add clear disclosures and consent screens. LG followed in May 2026 with a settlement requiring a pop-up disclosure on its TVs and a simple way to opt out. As of the attorney general’s May announcement, the cases against Sony, Hisense and TCL were still ongoing.

Those deals cover Texas. If you live elsewhere, the settings on your TV are still yours to check.

Where the viewing data goes

Vizio, now owned by Walmart, publishes the most detailed description of what happens next. Its Viewing Data covers shows, ads, games, connected devices and external apps, and it is tied to your IP address and a device identifier. If you sign in with a Vizio or Walmart account, it can be linked to that account as well. The TV also periodically collects the MAC addresses of nearby Wi-Fi access points, which work like a fingerprint of where the TV sits.

Vizio licenses that data to selected partners, who may combine it with information from data brokers and advertisers: demographics, smartphone location, web history and purchase history. One example from Vizio’s own text is a partner checking whether a phone that shares an IP address with the TV later visited a store after a commercial aired. No name is required for that. The shared IP address links the big screen to the phones on the same network. We walked through how phones get profiled in our piece on the advertising ID.

How to turn off ACR on your TV

Every platform names this differently, and menus move around between software versions. The paths below come from the companies’ help pages and statements. If a menu looks different on your set, the built-in manual in the settings usually has the current path.

On Samsung TVs the feature is called Viewing Information Services. Samsung’s US help page says ACR only runs if you consented to that notice during setup or turned it on later, and that you can switch it off in the Settings menu at any time. The page does not spell out the menu path. Look in the privacy section of the settings for the list of terms you agreed to and withdraw consent for Viewing Information Services.

On LG TVs, ACR runs only if you accepted the Viewing Information agreement. LG says so in a statement published in Austria, adding that ACR is off by default and that consent can be withdrawn in the TV settings. Consumer Reports found the agreement under All Settings, Support, Privacy & Terms, User Agreements. Withdraw consent there. In the study, ACR traffic appeared after consent was given during setup, so if you accepted everything back then, it is on. LG’s manual for 2024 webOS models also lists a feature called Live Plus under All Settings, General, System, Additional Settings. Turn that off too. Older webOS versions put Additional Settings directly under General.

Roku says ACR is not enabled out of the box. To check, press Home, go to Settings, then Privacy and Smart TV Experience, and make sure Automatic Content Recognition (ACR) is unchecked. You can also do this at my.roku.com under Privacy Settings. Roku adds that data collected while the setting was on stays with Roku after you turn it off.

On Vizio TVs, go to All Settings, Privacy & Legal, Viewing Data. Older models use All Settings, Admin & Privacy, Viewing Data instead. Vizio says turning it off deletes logged Viewing Data from its database and does not affect the TV’s performance.

Fire TV smart TVs keep the switch under Settings, Preferences, Privacy Settings, Automatic Content Recognition, according to Amazon. Turning it off does not change whether you see ads, only how repetitive they may get.

Google TV itself does not use ACR, Google told Consumer Reports. The TV makers that build on it can add their own. Sony’s Bravia sets, for example, come with a separate privacy notice for Samba TV, an ACR company. On Sony, TCL or Hisense sets, look through the maker’s own privacy screens for anything about viewing information, program recommendations or sharing TV data.

What switching off ACR does not cover

ACR is one channel among several. Turning it off stops the TV from fingerprinting your screen, and the rest keeps running.

Every app collects on its own. Netflix knows what you watch on Netflix, and no TV setting changes that. The platform account adds another layer. Google’s help page for Google TV lists, among other things, your watchlist and watch activity, installed apps, app interactions and device IDs. The same page notes that Google or third parties may still get your general location from your IP address when location is off.

Your TV also has an advertising ID, just like your phone. On Google TV you can delete it under Settings, Privacy, Ads. You will still see ads, but they will be less personal. On Vizio, turning off Viewing Data does not stop what the company calls Activity Data, which it uses to recommend content.

A lot of worry about smart TVs is really about the microphone. ACR does not use one. It works from the picture or the audio of what is already playing. Voice control is a separate setting, and if you are wondering why ads seem to follow your conversations, our article Is my phone listening to me? covers the more likely explanations.

One more trap. A factory reset runs you through setup again, consent screens included. Tapping “accept all” at that point can switch ACR right back on.

A streaming stick and an offline TV

If you want to settle the question for good, take the TV off the network. Without a connection it cannot send fingerprints anywhere, whatever the settings say. Antenna, cable and console still show up fine.

A streaming stick or small box on an HDMI port then handles the apps. It is not a clean slate. The stick has its own maker, its own account and its own advertising ID. But it only sees what plays inside its own apps, not the antenna feed or the console on the next input. Order matters here. A stick plugged into a TV that is online with ACR turned on changes little, because the TV sees the stick’s picture too.

The offline route has one cost. A TV that never connects never gets software updates. For a set that only displays a picture, that is a small risk. If you rely on the TV’s own apps or voice control, the menu switches are the better choice.

The short version

Automatic content recognition is not spy-movie surveillance. It is a measurement tool for advertisers, built into many smart TVs and switched on with one tap during setup.

So, once per TV: withdraw the Viewing Information agreement and turn off Live Plus on LG, withdraw consent for Viewing Information Services on Samsung, uncheck ACR on Roku, switch off Viewing Data on Vizio and Automatic Content Recognition on Fire TV. On Google TV sets, go through the maker’s privacy screens and delete the advertising ID. After a factory reset, check again. If you want to go further, keep the TV offline and stream from a stick. Apps and platform accounts will still collect what happens inside them. What comes in over the antenna or the console, though, stays in your living room.

Frequently asked questions

What is ACR on a TV?

ACR stands for automatic content recognition. The TV takes small samples of the picture or the audio at short intervals, turns them into a digital fingerprint and sends that fingerprint to a server. The server compares it with a library of shows, movies and commercials. When there is a match, the platform knows what is on your screen at that moment. Roku compares it to music identification apps like Shazam, which is a fair comparison.

Can my TV see what I play through HDMI?

It can. A 2024 measurement study found ACR traffic on LG and Samsung TVs while a laptop or a game console was plugged in over HDMI. Vizio, Roku and Amazon also describe recognizing content from connected devices such as cable boxes or streaming sticks. Netflix and YouTube played inside the TV apps produced no ACR traffic in that study.

Does turning off ACR actually work?

On the TVs that have been tested, yes. In the 2024 study, traffic to the ACR servers stopped completely once the researchers declined all advertising and tracking options on the LG and Samsung sets, both in the US and in the UK. Turning off ACR does not stop apps, your platform account or the advertising ID from collecting their own data.

Is my smart TV listening to me through a microphone?

ACR does not need a room microphone. It fingerprints the picture or the audio of whatever the TV is playing, the signal it already has. A microphone in the remote or the set for voice control is a separate feature with its own settings.

Should I just keep my smart TV offline?

For ACR, that is the most thorough fix, because a TV without a connection cannot send fingerprints anywhere. You can plug in a streaming stick for apps and leave the TV itself disconnected. The stick has its own maker, account and data collection, but it only sees what plays in its own apps, not the antenna feed or the console on another input.