Delta Chat vs K9 Chat
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Delta Chat
This decentralized messenger offers private, secure, and reliable instant messaging. It allows for easy setup on multiple devices and supports multiple chat profiles without requiring a phone number. Enjoy end-to-end encryption and the flexibility to run it with your own email or server.
- Decentralized instant messaging
- Private onboarding without phone number
- End-to-end encryption
- Multiple chat profiles
- Works on multiple devices
- Self-hosted option
Read full descriptionHide full description
Delta Chat is a reliable decentralized instant messenger that is easy and fun to use for friends, family, groups and organizations. Delta Chat is developed by a dedicated FOSS contributor community that jointly releases refinements and new features several times a year, across many stores and platforms world-wide. Features at a glance: • Private. Instant on-boarding without a phone number or other private data. • Friends & Family: Only chat with people you know. Unknown users cannot message or follow you without mutual consent. • Flexible. Supports multiple chat profiles and is easy to setup on multiple devices. • Reliable. Works under bad and adversarial network conditions. • Secure. Audited End-to-End encryption safe against network and server attacks. • Sovereign. Can be run with your own e-mail address or server. • FOSS. Fully Open Source/Free Software, built on Internet Standards.
K9 Chat
This secure chat application offers end-to-end encryption and zero-trust communication for private teams and organizations. It supports audio, video, screensharing, and voice notes without tracking user activity. Access requires an account provided by an administrator.
- End-to-end encryption
- Zero-trust communication
- Anonymous messaging
- Audio and video calls
- Screensharing
- Voice notes
Read full descriptionHide full description
K9 Secure chat is an End-To-End Encrypted, "Zero Trust" based chat application providing anonymous communications without tracking possibilities - Audio, Video, Screenshare, Voice notes, and much more without efforts Note: Only usable with K9 servers - on-premise, cloud-based, or hybrid over secure networks maintaining the most possible level of security in communications within entities, governments, and closed teams. This app is not open for the public, Only download if you have access to a K9 Chat secure account provided by your administrator
Screenshots
Verdict
The clearest difference is rating: K9 Chat at 5.0 against Delta Chat's 4.5. Delta Chat's advantage is ratings volume (122 vs 1) and iOS requirement (15.6 vs 18.5). On price, update cadence, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
K9 Chat holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Delta Chat has 122 ratings behind it against 1, so its average is the more settled of the two.
Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on September 24, 2026 and July 21, 2026 respectively.
| Parameter | Delta Chat | K9 Chat |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (122 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 61.2% of reviews | — |
| Number of ratings | 122 — better | 1 |
| Update frequency | Every 3 weeks | Every 3 weeks |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.6 — better | 18.5 |
| Further details — not scored | ||
| Size | 60 MB | 250 MB |
| Age rating | 4+ | 4+ |
| Developer | merlinux | Colohost LLC |
Customer experience
Delta Chat
K9 Chat
In-app purchases
Delta Chat
No in-app purchases
K9 Chat
No in-app purchases
