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Frequently Asked Questions

How to use it

Troubleshooting

Privacy and security

Funding and business model

How to use it

I have nobody to chat with! Where can I find any groups?

Please check our Groups Directory in the first place. You might find some interesting groups and meet even more interesting people.

What is database? What can I do with it?

Database is essential for SimpleX Chat to function properly. In comparison to centralized messaging providers, it is the user who is responsible for taking care of their data. On the other hand, user is sure that nobody but them has access to it. Please read more about it: Database.

Can I send files over SimpleX?

Of course! While doing so, you are using a state-of-the-art protocol that greatly reduces metadata leaks. Please read more about it: XFTP Protocol.

What’s incognito profile?

This feature is unique to SimpleX Chat – it is independent from chat profiles.

When "Incognito Mode” is turned on, your currently chosen profile name and image are hidden from your new contacts. It allows anonymous connections with other people without any shared data – when you make new connections or join groups via a link a new random profile name will be generated for each connection.

How do invitations work?

It is quite a complex process, but fortunately all of this happens in the background, so it's simply to use.

Whenever somebody connects to you via your address, they basically ask your client whether they want to establish connection. After that, you can either agree or disagree.
If interested, please read more: Addresses and invitations.

How to configure and delete groups?

Please check: Users guide.

Are there any reactions to messages? Can I answer specific messages directly?

Yes! Currently, there are six emojis available. What's more, you can respond to specific message by holding it and selecting Reply.

What do checkmarks mean?

It's quite simple:

  • one checkmark - message is delivered to the relay (the server).
  • two checkmarks - message is delivered to the recipient's device.
    "sent" means accepted by the relay for delivery, "delivered" - stored on the recipient device.

Also see: I do not see the second tick on the messages I sent

I want to see when my contacts read my messages

To know when your contact read your messages, your contact's app has to send you a confirmation message. And vice versa, for your contact to know when you read the message, your app has to send a confirmation message.

The important questions for this feature:

  • do you always want that your contacts can see when you read all their messages? Probably, even with your close friends, sometimes you would prefer to have time before you answer their message, and also have a plausible deniability that you have not seen the message. And this should be ok - in the end, this is your device, and it should be for you to decide whether this confirmation message is sent or not, and when it is sent.
  • what practical problems an automatic notification sent to your contacts when you read the message solves for you compared with you simply adding a reaction to a message or sending a quick reply?

Overall, it seems that this feature is more damaging to your communications with your contacts than it is helpful. It keeps senders longer in the app, nervously waiting for read receipts, exploiting addictive patterns - having you spend more time in the app is the reason why it is usually present in most messaging apps. It also creates a pressure on the recipients to reply sooner, and if read receipts are opt-in, it creates a pressure to enable it, that can be particularly damaging in any relationships with power imbalance.

We think that delivery receipts are important and equally benefit both sides as the conversation, as they confirm that communication network functions properly. But we strongly believe that read receipts is an anti-feature that only benefits the app developers, and hurts the relations between the app users. So we are not planning to add it even as opt-in. In case you want your contact to know you've read the message put a reaction to it. And if you don't want them to know it - it is also ok, what your device sends should be under your control.

Can I use the same profile on desktop? Do messages sync cross-platform?

You can use your profile from mobile device on desktop. However, to do so you need to be on the same network, both on your mobile and desktop. More about it: Release info.

Why cannot I delete messages I sent from my contact's device?

In SimpleX Chat, you and your contacts can delete the messages you send from recipients' devices if you both agree to that within 24 hours of sending it. To be able to do that you both have to enable "Delete for everyone" option in Contact preferences - tap on the contact's name above the conversation to get there.

You can also revoke the files you send. If the recipients did not yet receive the file, they will not be able to receive it after the file is revoked.

This is different from most other messengers that allow deleting messages from the recipients' devices without any agreement with the recipients.

We believe that allowing deleting information from your device to your contacts is a very wrong design decision for several reasons:

  1. it violates your data sovereignty as the device owner - once your are in possession of any information, you have the rights to retain it, and any deletion should be agreed with you. And security and privacy is not possible if users don't have sovereignty over their devices.
  2. it may be a business communication, and either your organization policy or a compliance requirement is that every message you receive must be preserved for some time.
  3. the message can contain a legally binding promise, effectively a contract between you and your contact, in which case you both need to keep it.
  4. the messages may contain threat or abuse and you may want to keep them as a proof.
  5. you may have paid for the the message (e.g., it can be a design project or consulting report), and you don't want it to suddenly disappear before you had a chance to store it outside of the conversation.

It is also important to remember, that even if your contact enabled "Delete for everyone", you cannot really see it as a strong guarantee that the message will be deleted. Your contact's app can have a very simple modification (a one-line code change), that would prevent this deletion from happening when you request it. So you cannot see it as something that guarantees your security from your contacts.

When "Delete for everyone" is not enabled, you can still mark the sent message as deleted within 24 hours of sending it. In this case the recipient will see it as "deleted message", and will be able to reveal the original message.

You can replace https://simplex.chat/ with simplex:/ or with any other domain - the app never connect with it, ignoring it completely. It is only used to make it easier to connect for the new users who did not install the app yet.

The invitation links will soon move to servers' domains. The servers already can host the pages that will be used to show QR codes.

The link itself and the key exchange are not hosted anywhere, and the server that hosts the page to show QR code does not observe the actual connection link, because it is in the hash part of the link. The part after hash character (#) is not sent over the internet - the server can only see https://simplex.chat/contact/ and the rest is processed on user's device in the browser, if you open it as a page.

Troubleshooting

I do not receive messages or message notifications

There may be several reasons messages are not delivered to you from your contact:

You or your contact cannot connect to the server that you use to receive messages from your contact.

You can check which server is used to receive messages by tapping the contact name above the conversation.

You can also run tests for this server from the app Network settings.

Please ask your contact if they have a single tick on the message to determine if the message failed to send or if you fail to receive it.

Message delivery got stuck because of some unresolved bug.

Fully restarting the app is the workaround to resume message delivery.

To do it on iOS, simply close the app (swipe up from the opened apps) and open it again.

To do it on Android - choose Restart from the app settings, simply closing and re-opening the app will not restart the messaging service.

Your Android operating system kills the app while it is in background.

Check battery settings for the app - it should be set to Unrestricted.

For some devices, there may be additional options to prevent the app from being killed - e.g., on Xiaomi you need to enable Auto Start setting for the app. Please consult https://dontkillmyapp.com site for any additional settings for your device.

Why my notifications aren't working on iOS

Check the color of the bolt icon next to Notifications in app settings - it should be green.

If it's not, please open notifications, disable them (choose Off / Local), and then enable again - you should do it when you have Internet connection.

Check if your push server has been restarted at time of the issue (Notifications -> Push server) at https://status.simplex.chat if it has been restarted, you may not receive notifications from that time.

If device was offline, you may need to open the app to start receiving notifications.

If the above didn't help, the reason could be that iOS failed to issue notification token - we have seen this issue several times. In this case, restarting the whole device should help.

In some cases notifications may still not work, iOS notifications are hard to do right in a decentralized app, we will be improving them soon to be more reliable.

Messaging server or notification server is under maintenance

Please check the current status of preset servers at https://status.simplex.chat. You can also connect to status bot via QR code on that page - it will send the updates when the server is offline for maintenance, and also when the new versions of the app are released.

I do not see the second tick on the messages I sent

You may not have the second tick on your sent messages for these reasons:

  • your contact is not online, and did not receive your message.
  • possibly, message delivery to your contact or to you is disrupted - see I do not receive messages - please check with your contact via some other channel if they received your message. If the message was delivered, then it means your device could fail to receive the delivery notification.
  • possibly, your contact disabled sending delivery receipts - it can be disabled for specific or for all contacts - please check with your contact.

I see image preview but cannot open the image

It can be for these reasons:

  • your contact did not finish uploading the image file, possibly closing the app too quickly. When the image file is fully uploaded there will be a tick in the top right corner or the image
  • your device fails to receive it. Please check server connectivity and run server tests, and also try increasing network timeouts in Advanced network settings. File reception was substantially improved in v5.7 - please make sure you are using the latest version.
  • file expired and can no longer be received. Files can be received only for 2 days after they were sent, after that they won't be available and will show X in the top right corner.

I cannot play a voice message

This can happen for similar reasons as for images.

Please check your network settings and make sure you use the latest version of the app.

Please report such issues if you use v5.7 or newer.

Audio or video calls do not connect

App uses WebRTC for calls. Please check that you can connect to the servers configured in the app: stun.simplex.im and turn.simplex.im - see troubleshooting WebRTC.

If you can connect to the server, please report this issue to us privately, including the following information:

  • how you connect to the network: WiFi, mobile network, VPN provider - the more information you can provide the better.

  • app version and platform. For mobile apps, it would help if you can make a screen recording from both devices during unsuccessful calls and share with us.

  • if the issue is on desktop app, which browser is used for calls. In this case also please check browser console during the call and send us the log, ideally from both sides of the unsuccessful calls.

Thank you for helping us debug and improve calls.

Audio or video calls without e2e encryption

During the call, the app indicates whether or not the call has end-to-end encryption.

If one of the call parties uses Android (or desktop) app, the call would use Android system webview (or browser). Some older systems do not support media stream encryption, in which case the call will connect without it.

To determine whether it is the limitation of your, your contact's or both devices:

  • if some of your calls have e2e encryption but some don't, then it's certainly the old webview version or browser of your contacts - please ask them to upgrade.
  • if you are not sure, you can check at what point "no e2e encryption" appears:
    • if it is shown when the call rings on your device, then your contact's device does not support call encryption.
    • if it is shown on your screen as soon as you start the call, then your device does not support call encryption.
    • if in the beginning of the call your device shows "e2e encryption" but when your contact accepts the call it changes to "no e2e encryption", then it is only your contact's device that does not support it.

You need to upgrade webview (some Android systems allow it), Android system or the device to have support for e2e encryption in the calls - all modern WebViews (and browsers) support it.

If you confirmed the connection in the app, pending connection will be shown in the list of chats - you can assign the name to it, so you know who it was when your contact is connected (e.g., if they choose some name you don't recognize).

For connection to complete, your contact has to be online and have the app running - please ask them to open the app, and try to have the app open at the same time - it will help to complete the connection faster.

Once the connection is established you don't need to be online at the same time to send messages.

I do not know my database passphrase

If you are prompted to enter database passphrase and you do not know it, this could have happened due to:

  • You may have forgotten the passphrase. (There is no other way to access your data).
  • Migration of app data from one device to another while using unsupported migration process, e.g. via iCloud backup. Use SimpleX Chat's own migration process in the app Settings.

In the previous desktop app versions it could also happen in case of error during SimpleX Chat installation.

You can resolve it by deleting the app's database: (WARNING: this results in deletion of all profiles, contacts and messages)

  • on Android/iOS, uninstall the app and install it again.
  • on Windows, delete folder C:\AppData\Roaming\SimpleX, you can find it by pressing Windows key + R and entering %appdata%.
  • on Linux/Mac, delete directories ~/.local/share/simplex and ~/.config/simplex, where ~ represents your home directory (/home/user)
  • on Flatpak, delete directory ~/.var/app/chat.simplex.simplex.

Privacy and security

Does SimpleX support post quantum cryptography?

Yes! Please read more about quantum resistant encryption is added to SimpleX Chat and about various properties of end-to-end encryption in this post.

What user data can be provided on request?

Our objective is to consistently ensure that no user data and absolute minimum of the metadata required for the network to function is available for disclosure by any infrastructure operators, under any circumstances.

Please see our Privacy Policy and Transparency Reports.

Does SimpleX protect my IP address?

Yes!

SimpleX Chat from version 6.0 uses private message routing whenever you send messages to unknown servers (all servers in app network settings, both enabled and not, are considered "known").

For private routing to work, the servers chosen by your contacts (and by the group members in your groups) must be upgraded to the recent versions. Messaging servers include support for private routing from v5.8, but we recommend using the latest versions.

If the servers didn't upgrade, the messages would temporarily fail to deliver. You will see an orange warning icon on the message, and you can decide if you want to deliver them by connecting to these servers directly (it would require changing network settings). At the time of writing (August 2024), all preset servers and absolute majority of self-hosted servers we can see on the network support private message routing.

With private routing enabled, instead of connecting to your contact's server directly, your client would "instruct" one of the known servers to forward the message, preventing the destination server from observing your IP address.

Your messages are additionally end-to-end encrypted between your client and the destination server, so that the forwarding server cannot observe the destination addresses and server responses – similarly to how onion routing work. Private message routing is, effectively, a two-hop onion packet routing.

Also, this connection is protected from man-in-the-middle attack by the forwarding server, as your client will validate destination server certificate using its fingerprint in the server address.

You can optionally enable private message routing for all servers in Advanced network settings to complicate traffic correlation for known servers too. This will be default once the clients are improved to "know about" and to take into account network server operators.

See this post for more details about how private message routing works.

Doesn't private message routing reinvent Tor?

No, it does not!

It provides better privacy for messaging than Tor, and it can be used with and without Tor or other means to additionally protect your traffic from known servers as well.

Tor, VPN and other transport overlay networks route sockets, by creating long-lived TCP circuits between you and the destination server. While it protects your IP address, it does not protect your activity within this circuit. E.g., if you visit a website via Tor, it can still observe all pages you view within a session. Likewise, if you were connecting directly to a messaging server via Tor, this server would be able to list all message queues you send messages to.

Private message routing routes packets (each message is one 16kb packet), not sockets. Unlike Tor and VPN, it does not create circuits between your client and destination servers. The forwarding server creates one shared session between itself and the destination, and forwards all messages from you and other clients to that destination server, mixing messages from many clients into a single TCP session.

As each message uses its own random encryption key and random (non-sequential) identifier, the destination server cannot link multiple message queue addresses to the same client. At the same time, the forwarding server cannot observe which (and how many) addresses on the destination server your client sends messages to, thanks to e2e encryption between the client and destination server. In that regard, this design is similar to onion routing, but with per-packet anonymity, not per-circuit.

This design is similar to mixnets (e.g. Nym network), and it is tailored to the needs of message routing, providing better transport anonymity that general purpose networks, like Tor or VPN. You still can use Tor or VPN to connect to known servers, to protect your IP address from them.

Why don't you embed Tor in SimpleX Chat app?

Tor is a fantastic transport overlay network - we believe it might be the best there is right now. If its threat model works for you, you absolutely should use it - SimpleX Chat app supports Tor via SOCKS proxy since v3.1, and SimpleX network servers can be available on both public and onion address at the same time since v3.2, improving anonymity of the users who use Tor.

If you host your messaging server on the onion address only, the users who don't use Tor would still be able to message you via private message routing - all preset servers are configured to forward messages to onion-only servers.

But there are many reasons not to embed Tor in the app:

  • it increases response latency, error rate, and battery usage, and we believe that for most users enabling Tor by default would be a bad trade-off.
  • it would require us regularly updating Tor library in the app, and your Tor integrity would depend on us – you would be "putting too many eggs in one basket".
  • some networks restrict Tor traffic, so the app UI would have to support advanced Tor configuration, diverting our limited resources from the core app features that benefit all users.
  • some countries have legislative restrictions on Tor usage, so we would have to support multiple app versions, also increasing our costs and slowing down the progress.

The last, but not the least, it would create an unfair competitive advantage to Tor. We believe in competition, and we want our users to be able to choose which transport overlay network to use, based on what network threat model works best for them.

If you want to use Tor or any other overlay network, such as i2p, Nym network, Katzenpost, etc., you need to research their limitations, because none of them provides absolute anonymity against all possible attackers.

And if after that research you decide to use Tor, it takes about 2 minutes to install and start Orbot app. We believe that if it seems complex, then you should not be using Tor - it is an advanced technology that can only improve your privacy and anonymity if you understand its limitations and know how to configure it.

Can I host my own relays?

Of course! Please check these tutorials: SMP server and XFTP server.

Funding and business model

How are you funded?

SimpleX Chat Ltd is funded by private investors and venture capital. As an open-source project, it is also being generously supported by donations as well. Read the posts from 2023 and from 2024 for more details.

Why VCs?

Here are some reflections on VC funding being a necessity for a project at this scale, as well as sustainability and profitability for longtime operations: https://www.poberezkin.com/posts/2023-10-31-why-privacy-impossible-without-venture-funding.html

And another perspective from a team member on the delicate balance of venture-backed and nonprofit structures, and the plans for the SimpleX network protocols to evolve under the stewardship of nonprofit entities in various jurisdictions, so that its continued evolution aligns more closely with the vision of community-driven, independent and transparent governance:
https://simplex.chat/blog/20240404-why-i-joined-simplex-chat-esraa-al-shafei.html.

What will be the business model?

We are focusing on product-market fit, and as such the business model is still a work in progress. However, the app will have a freemium model with extra features or capabilities for paid users (taking into consideration a potential formula like 5% paying $5/month is $3/user/year - ~90% gross profit margin).

The other income stream would be via business services, for entities needing direct and customized support to integrate with the SimpleX protocol or related resources. There will also be a revenue-sharing model from customers to network operators, to provide an incentive for them to continue running nodes, which will increase decentralization and reliability of the network.

Non-exploitative commercial models with fully open source code are not easy to achieve, and we’re committed to finding the best possible fit for our context. Everything will be fully communicated as this plan progresses.

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