When comparing Telegram vs Signal, the Slant community recommends Signal for most people. In the question“What is the best team chat software?” Signal is ranked 2nd while Telegram is ranked 3rd. The most important reason people chose Signal is:
Signal uses an advanced end to end encryption protocol that provides privacy for every message every time.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Free and convenient large file sharing
Copy/paste videos, gifs, images, geolocation, documents, and even executable files. Drag over files for practically any time up to 2GB in size. Images can be compressed, too.
Pro Free of cost
The application is available free of cost.
Pro Privacy focused
In addition to the end-to-end encryption [only in secret chats] that provides privacy to communications, the app also includes self destructing timers for chats, and the ability to permanently delete messages, yours and theirs, from your and their devices.
Pro Media messaging
Videos, gifs, images, geolocation, and documents.
Pro Channels for one way broadcasting
Broadcasting channels suitable for announcing things.
Pro Beautiful UI
Very customizable with a lot of clean looking options.
Pro Possible to send photos and videos without compression
Pro Supergroups of up to 200,000 people
In Supergroups, anyone along with admins can delete their messages from all sides. A message can be pinned to the top. All of the user's messages can be deleted by an administrator, and they can be banned and reported as well. Supergroups can have a public link (outside of Asia, due to high spam volumes), which is also a username.
Pro Two-step verification
You can set up an additional password to your account, which can be reset by your email. You don't have to use an email if you do not want to. If you lose access to your email or forget your password, you will be able to reset it via text message if your account is over seven days old and will receive it within a week (in case you recover anything before then).
Pro Secure
Pro Saved messages
You can write messages to yourself. You can write some notes, add links, and see everything across all your devices.
Pro Cloud chat keys are kept in different jurisdiction
Even though encryption used for cloud-based storage (e.g. Gmail, Facebook, iCloud) may not be as secure as end-to-end encryption or zero-knowledge storage, Telegram does the most that it can by holding keys to chats in different jurisdictions, requiring intergovernmental cooperation to obtain the keys. This is aside from whatever other security measures have been taken, of course.
Pro Multiplatform native client apps
There are native desktop, mobile and web client apps, that are optimized for speed and are light on memory usage.
Pro Open source client apps
Client apps are open source, making whole service more trustworthy.
Pro Unlimited storage
Unlimited number of files can be stored forever on the cloud. You can upload files up to 1.5 GB each.
Pro Voice and video messages
You can post voice and video messages if you are too lazy to write text messages.
Pro Group Voice Chat
This Discord-like feature adds to the interactivity of the application.
Pro Pinned Messages
You can pin messages to the top of groups or supergroups so members will see them when opening the group.
Pro Self-destruct messages
Messages in individual chats can be set to self destruct on a timer. They will disappear after the timer expires.
Messages in all new chats can be set to self-destruct with a global auto-delete timer in Settings > Privacy and Security > Auto-Delete Messages.
Pro Edit or delete messages after sending them
Pro Banned in China
Pro Save time with inline bots and link previews
Unfortunately, on the desktop videos don't play, but images are viewable without visiting popular websites like imgur and Instagram.
You can play YouTube videos and others within the app, so you don't need to embed code or anything.
With inline bots, such as @gif, @pic/bing, @vid/YouTube, etc, you can look things up without leaving the client or chat that you're in. Simply type the name and some keywords and wait for the results to load.
Pro @mentions
You can ping people to get their attention by @mentioning them.
Pro Desktop app handles HiDPI
The desktop app has a built in setting to scale the UI of the app up to 200% which allows for those with 4k monitors/screens to use the app without scaling issues.
Pro High quality calls
Uses the latest GPL audio codecs, such as Opus, an adaptative high-quality codec that supersedes AAC at any bitrate.
Pro Customer support is within the app
Although it's volunteer based, but still pretty top-notch if available, which it tends to be.
Pro Large groups can have channels called 'Topics'
Topics are now available in groups of 100+ members and have a sleek two-column layout and new buttons to quickly navigate.
A default topic called General is now in every topic group, holding the group’s service messages and previous message history.
Pro Popular in the USA
On SimilarWeb you can see that Telegram is on the top 15 among all communication apps.
Pro Provides security and privacy
Signal uses an advanced end to end encryption protocol that provides privacy for every message every time.
Pro Free and open source
Signal is free and open source software, enabling anyone to verify its security by auditing the code. It's the only private messenger that uses open source, peer-reviewed cryptographic protocols to keep your messages safe.
Pro Supports encrypted group chats
Pro Has a desktop app
Signal Desktop can be used on multiple devices and has most features of the Android version, although it still requires you to register with your phone.
Pro Supports sharing of various different media types
Signal supports: emoji, pictures, videos, audio, contacts, any location and GIF.
Pro Note to Self feature
Allows you to "send: messages to yourself and sync to desktop so you can use Signal as a kind of encrypted Pushbullet alternative
Pro You can easily view all media exchanged
You can easily view all media shared in the chat without scrolling back to when it was shared.
Pro Annonymous Sender (Encrypted)
The sender credentials can be encrypted with the rest of the message, leaving only the recipient address readable by the Signal server. Even if Signal wanted they couldn't see who is talking with who by this mean.
Pro Works everywhere in every country
Unlike most messenger apps, Signal works reliably in all countries by securely circumventing internet censorship.
Pro Recommended by Edward Snowden
Edward Snowden uses this messenger and recommends it to everyone who is concerned about his privacy.
Cons
Con Not fully open source
Telegram has an open API and protocol free for everyone, but the backend software is not open source. Therefore 100% privacy can not be evaluated.
Con Can only be used with a phone number
It is not possible to activate and use Telegram by mail etc. You need a phone number.
Con Only "Secret Chat" messages are encrypted end to end
The only way to get end-to-end encryption (client-client) using Telegram is to use the Secret Chat function, anything through the service is server-client encrypted. Also secret chat is only implemented in the mobile apps, meaning there is no way to encrypt messages end-to-end when using the desktop client or the web browser client.
Con "Secret Chat" feature is not available for desktop client
Secret chats with end to end encryption are only available on mobile apps.
Con No source code sintax highlighting
Telegram does not have source code syntax highlighting, making it difficult to share code snippets.
Con Does not work for visually impaired
Doesn't work for visually impaired.
Con Does not support spherical 360° photos
Spherical 360° photos becoming more popular these days, but Telegram does not support such format.
Con Does not support text messaging
You can NOT make it your default text messaging App.
Con Needs access to your phone number and contacts to work
Con Single device
Signal can only be registered to one mobile device at a time. But you can link Signal to Signal Desktop.
Con Servers hosted in the US
A security risk due to National Security letters, which require giving up data to the US state, and making it illegal to disclose that.
Con Unreliable notifications
Sometimes messages won't be received if the Signal app has been closed for a long time or hasn't been opened after booting the device.