Signal vs Telegram: Real-World Privacy Test

Telegram passed a major milestone in March 2025 when founder Pavel Durov announced the app had surpassed 1 billion monthly active users, making it the world's second most-used messaging app behind WhatsApp. Signal's growth has followed a different pattern: after WhatsApp updated its data-sharing terms in January 2021, Signal's weekly installs jumped 43 times over the prior week as users went looking for an alternative built around privacy rather than scale.

Both apps market themselves as the private choice, and both get compared constantly, but "encrypted messaging app" means something different depending on which one you open. Signal encrypts everything by default. Telegram encrypts almost nothing by default and asks you to opt in, chat by chat, to get the protection most users assume they already have.

That gap creates real, everyday problems for anyone choosing between them. Group chats behave differently on each platform, metadata piles up in ways that are easy to miss, and ownership structures determine who actually has the power to comply with a government request. This comparison walks through the actual technical and corporate facts, not marketing claims, to settle which app holds up under scrutiny.

The Real Challenges With Comparing Messaging App Privacy

• Default encryption is not obvious. Telegram's standard chats look identical to its encrypted ones, so most users never realize their everyday conversations are not end-to-end encrypted.
• Group chats are the biggest blind spot. Telegram has no end-to-end encrypted group option at all, and many users assume group privacy matches one-to-one privacy.
• Metadata is invisible but revealing. Who messaged whom, when, and from what IP address can expose a social graph even if message content stays private.
• Ownership and jurisdiction are hard to verify. Corporate structure determines what a company can be legally compelled to hand over, but that structure is not always disclosed.
• "Encrypted" and "audited" are not the same claim. A protocol can be encrypted and still be closed to outside review, which matters when a company asks users to simply trust its implementation.

Quick Comparison

Here is the Signal vs Telegram breakdown across the factors that actually determine privacy, before the deeper explanation of each one.

Default Encryption: Signal Protocol vs MTProto

Signal encrypts every one-to-one chat, group chat, and call end-to-end by default, using the Signal Protocol, with no setting to turn on and no exception for group conversations. There is no non-encrypted mode to accidentally fall back to.

Telegram works differently by design. Its official documentation explains that Cloud Chats use server-client encryption, while only Secret Chats add a further layer of client-client end-to-end encryption, and Secret Chats are opt-in, one-to-one only, and tied to a single device. Cryptographer Matthew Green put the practical effect bluntly: "the vast majority of one-on-one Telegram conversations, and literally every single group chat, are probably visible on Telegram's servers", since Secret Chats require both users to be active on the same device and take several extra taps to start. Mozilla Foundation's review reached a similar conclusion, noting that Telegram's calls are end-to-end encrypted by default, but its messages and files are not unless a user manually opens a Secret Chat.

Metadata Collection and Sealed Sender

Message content is only half the privacy picture. Signal has built its architecture to minimize the metadata it can see in the first place, and its 2018 sealed sender feature strips the sender's identity from the outer envelope of a message, so Signal's own servers cannot easily see who is messaging whom, only who the recipient is.

Telegram collects a wider set of account data by default. Mozilla's review found Telegram gathers phone numbers, usernames, profile pictures, contacts, and optionally location and email, and rated the app's privacy disclosures as lacking transparency on how that metadata is stored and who can access it. Neither company publishes a live metadata audit, but the architectural difference is documented: Signal is built to retain as little as possible, while Telegram's Cloud Chat model requires holding onto account and message metadata to sync chats across devices.

Group Chats: Where the Gap Is Widest

This is the single biggest practical difference between the two apps. Signal groups, which support up to 1,000 members according to the Signal Protocol's group messaging design, are end-to-end encrypted the same way a one-to-one chat is, with no separate mode to enable.

Telegram has no end-to-end encrypted group option whatsoever. Secret Chats are restricted to two people, which means every Telegram group, channel, and community, regardless of size or privacy setting, runs on the same server-side Cloud Chat encryption Telegram uses for ordinary messages. Anyone comparing the two apps for team or community chats, not just one-to-one conversations, is comparing a fully encrypted product against one that offers no end-to-end option at all in that category.

Open Source and Independent Verification

Signal makes its entire stack inspectable. Its Android, iOS, and desktop clients, the libsignal cryptographic library, and the Signal-Server backend are all published on GitHub, letting outside researchers examine the actual code implementing the encryption Signal claims to run.

Telegram publishes its client apps as open source, but its server backend, the part that actually stores Cloud Chat data and runs MTProto, is closed source. That means the encryption and storage claims in Telegram's own documentation cannot be independently verified against the real server code the way Signal's can. Green's analysis also flagged MTProto 2.0's custom "Infinite Garble Extension" encryption mode as a design choice that raises questions among cryptographers precisely because it departs from widely reviewed standards.

Ownership, Jurisdiction, and Business Model

Signal is developed by the Signal Foundation, a US-based 501(c)(3) nonprofit that launched in 2018 with a $50 million contribution from WhatsApp co-founder Brian Acton. It runs without advertising, investors, or a data-monetization model, which removes the financial incentive to collect more information than it needs.

Telegram's structure is harder to pin down. Its operating entity, Telegram FZ-LLC, is headquartered in Dubai with additional registration in the British Virgin Islands, and the company has been reported as generating substantial ad and subscription revenue as it has grown past a billion users. A for-profit company operating across multiple jurisdictions faces a different set of pressures and disclosure obligations than a single-country nonprofit, which matters directly when a government comes asking for data.

How Each Company Handles Government Requests

Signal's design has been tested in court, not just in policy documents. In response to a 2021 grand jury subpoena in California seeking user addresses, correspondence, and account details, Signal could only produce the Unix timestamp of account creation and the date of last connection, because that is the only data its architecture retains.

Telegram's policy shifted in 2024. Following founder Pavel Durov's arrest in France over allegations the platform ignored criminal activity, Telegram updated its terms of service to share a user's IP address and phone number with authorities in response to a valid legal request tied to a criminal case, a broader commitment than its prior policy of only disclosing data in terrorism-related court orders.

Where Telegram Genuinely Wins

None of this makes Telegram a bad product. Its Cloud Chat model syncs full chat history instantly across every device the moment you log in, something Signal's stricter architecture makes harder by design. Telegram also ships large file transfers, massive broadcast channels, bots, and a public API that Signal does not attempt to match, and its 1 billion-plus user base gives it a network effect Signal cannot compete with for casual, low-stakes chats. For a public channel, a large community, or moving big files, Telegram's feature set is genuinely ahead.

The Privacy Verdict

On the specific question of which app better protects a private conversation, the evidence favors Signal clearly. It encrypts everything by default, including groups, collects almost no metadata, publishes verifiable open-source code across its full stack, and has demonstrated in an actual subpoena response that it has almost nothing to hand over.

Signal strengths:

• End-to-end encryption by default on every chat, call, and group, with no setting to enable
• Sealed sender hides who is messaging whom from Signal's own infrastructure
• Client, protocol, and server code all published and independently verifiable on GitHub
• Nonprofit ownership with no advertising or data-monetization incentive

Signal weaknesses:

• Smaller user base makes it less useful for public channels or large broadcast audiences
• No native cross-device history sync as instant or seamless as Telegram's Cloud Chats
• Group size caps out lower than Telegram's largest channels and communities

Telegram remains a reasonable choice for public communities, large file sharing, and casual group chats where the content is not sensitive, but it is not the private option for anything you would not want stored on a company's servers.

Telegram strengths:

• Massive user base and network effect, over 1 billion monthly active users
• Instant cross-device sync and unlimited cloud chat history
• Large groups, public channels, bots, and file transfers Signal does not match

Telegram weaknesses:

• Cloud Chats and every group are not end-to-end encrypted by default
• Closed-source server backend that cannot be independently verified
• Confirmed policy of sharing IP address and phone number with authorities on legal request
• Collects more account metadata than Signal by design

How to Choose Between Signal and Telegram

If the conversation is sensitive, personal, or work-related and you want the strongest default protection, Signal is the better fit. Its encryption applies automatically, so there is no extra step to remember and no risk of forgetting to open a Secret Chat.

If you are running a large public community, sharing big files, or need instant history across five devices without a second thought, Telegram's Cloud Chat model still makes sense, as long as you treat anything typed there as visible to the company that runs the servers.

Whichever app wins your daily messaging, the rest of your privacy setup matters too. Block trackers and ads at the DNS level to control what leaves your phone beyond chat apps, and if account-based services worry you generally, our list of apps that work without an account at all covers other tools built the same way Signal is.

Whichever app you choose, download it from the official store listing rather than a third-party mirror, since a modified installer can undermine even the strongest encryption. Our guide on how to install an APK safely on Android walks through verifying a file's signature before you trust it with anything private.