2 Best Open-Source Alternatives to Element in 2026
By Noahlast updated pricing verified
Compared: open-source alternatives to Element
| Alternative | Best for | Standout | Biggest weakness | Learning curve | Price |
|---|---|---|---|---|---|
| Elementreference | government, defense, and enterprise organizations that need self-hosted, end-to-end encrypted chat with the option to federate across organizational boundaries | Matrix federation lets a self-hosted Element server exchange encrypted messages with users on entirely different organizations' servers, something closed platforms like Slack or Teams cannot do. | Enterprise and Sovereign pricing is not published; both require a sales conversation, and Enterprise pricing only applies from a 100-user minimum, making Element's paid tiers impractical to evaluate cost for small teams. | Moderate | Free |
| Mattermost | regulated, government, or defense organizations that need self-hosted, air-gapped, or sovereign-cloud team chat with compliance controls a SaaS-only tool like Slack can't provide | Deployment flexibility for compliance-sensitive organizations: the same platform can run fully air-gapped or in a sovereign cloud with FIPS 140-3/STIG-hardened compliance options, not available from mainstream SaaS chat tools. | No paid tier publishes flat per-user pricing; Professional, Enterprise, and Enterprise Advanced all require a sales conversation and prepaid annual seat commitment, making it harder to budget or compare cost against competitors up front, and self-hosting the free core requires ongoing server maintenance. | Moderate | Free |
| Rocket.Chat | regulated and security-conscious organizations (government, defense, healthcare, financial services) that need a self-hostable or air-gapped team chat platform, plus teams wanting a free, open-source Slack alternative | A fully open-source (MIT-licensed), self-hosted Community Edition with no user limit, alongside government and defense deployment options authorized up to DoD Impact Level 6 for classified environments. | None of the paid tiers publish list pricing — Commercial, Government, and Defense plans all require contacting sales for a quote, making it hard to budget or compare costs against competitors like Slack or Mattermost without a sales call. | Moderate | Free |
Element
Mattermost
Rocket.Chat1.Mattermost — best Element alternative for regulated, government, or defense organizations that need self-hosted, air-gapped, or sovereign-cloud team chat with compliance controls a SaaS-only tool like Slack can't provide
Mattermost is the best Element alternative for regulated, government, or defense organizations that need self-hosted, air-gapped, or sovereign-cloud team chat, staying closest to Element's own positioning for NATO, UN agencies, and European governments and militaries. Mattermost's core is free and MIT-licensed with no user limit, a more permissive license than Element's Community edition, which is AGPL-3.0, a copyleft license some organizations find more restrictive for commercial use. Mattermost's nearly 39,000 GitHub stars reflect an actively maintained open-core project, and it's used by organizations including the U.S. Air Force and NASA, a regulated-sector adoption track record comparable to Element's own government and defense customer base. Element remains the better choice for organizations that specifically need Matrix federation, letting a self-hosted Element server exchange encrypted messages with users on entirely different organizations' servers, a decentralized-communication capability Mattermost's more centralized deployment model doesn't offer the same way. Mattermost's Professional, Enterprise, and Enterprise Advanced tiers all require a sales conversation with no published flat pricing, matching the same lack of published pricing in Element's own Enterprise and Sovereign tiers. Mattermost's only external rating in our listing data is a single 5/5 Product Hunt review, thin evidence on either side of this comparison since Element itself has no ratings at all. For regulated deployments without Matrix's specific federation requirement, though, Mattermost's MIT-licensed core offers comparable compliance depth.
Compared to Element: MIT-licensed free core vs Element's AGPL-3.0-licensed Community edition, no Matrix-style cross-organization federation vs Element's core differentiator, both requiring a sales conversation for Enterprise-tier pricing
Wins:MIT-licensed free core is a more permissive license than Element's AGPL-3.0 Community edition, which carries copyleft terms some organizations find restrictive · Nearly 39,000 GitHub stars reflect an actively maintained open-core project with broad community adoption · Used by organizations including the U.S. Air Force, NASA, and Samsung, comparable regulated-sector trust to Element's own listed customers
Loses:No Matrix federation; Mattermost can't exchange encrypted messages across separate organizations' servers the way Element's decentralized architecture is built to do · Only a single 5/5 Product Hunt review on file, thin external validation matching Element's own lack of any external ratings · No published flat pricing for any paid tier; all require a sales conversation, the same gap in Element's own Enterprise and Sovereign tiers
Pros
- Self-hosted core is free (MIT-licensed) with no user limit, avoiding SaaS vendor lock-in.
- Deployment options (on-premise, private cloud, air-gapped) support compliance needs that pure-SaaS chat tools can't meet.
- Native apps across web, Windows, macOS, Linux, iOS, and Android.
- Open-core model means the underlying chat engine's code is auditable even though advanced features are commercially licensed.
Cons
- No published flat pricing for any paid tier; all require contacting sales and a prepaid annual commitment.
- Self-hosting the free core requires ongoing server maintenance, scaling, and upgrades.
- Advanced features (sovereign AI, high availability, air-gapped support) sit behind the commercial Enterprise license, not the open-source core.
- Smaller third-party app/integration ecosystem than Slack, which has a much larger app marketplace.
Pricing: Free — Free MIT-licensed core at $0; paid Professional/Enterprise/Enterprise Advanced tiers unpublished (contact sales) vs Element's free AGPL Community edition at $0, with Enterprise/Sovereign also requiring a sales conversation (verified undefined NaN, NaN)
2.Rocket.Chat — best Element alternative for regulated and security-conscious organizations (government, defense, healthcare, financial services) that need a self-hostable or air-gapped team chat platform, plus teams wanting a free, open-source Slack alternative
Rocket.Chat is the best Element alternative for teams that want a fully open-source, self-hostable chat platform with a similar open-core structure to Element's own Matrix-based product. Rocket.Chat's Community Edition is free under the MIT license with no user limit, and its over 46,000 GitHub stars mean the underlying code is fully auditable, a transparency comparable to Element's own AGPL-3.0-licensed Community edition. Rocket.Chat holds a 4.3/5 rating from 156 Capterra reviews, external validation Element's own listing has none of since Element carries no external ratings on file in our listing data. Rocket.Chat's Government and Defense tiers support air-gapped deployment with a DoD Authorization to Operate up to Impact Level 6, a level of regulated-sector deployment matching Element's own Sovereign tier positioning for government and defense customers. Element remains the better choice for organizations that specifically need Matrix's decentralized federation, letting a self-hosted Element server message users on entirely different organizations' servers without shared infrastructure, a capability Rocket.Chat's own federated communications feature approaches differently since it isn't built on the open Matrix protocol. Rocket.Chat's Commercial, Government, and Defense tiers all require a sales conversation with no published list pricing, matching the same lack of published pricing in Element's own Enterprise and Sovereign tiers. For self-hosted, auditable chat with an external rating Element's listing doesn't have, though, Rocket.Chat is a close structural match.
Compared to Element: 4.3/5 rating from 156 Capterra reviews vs Element's no external ratings on file, DoD Impact Level 6-authorized deployment vs Element's comparable Sovereign tier, federated communications vs Element's Matrix-protocol-based cross-organization federation
Wins:4.3/5 rating from 156 Capterra reviews, external validation Element's own listing has none of on file · Over 46,000 GitHub stars reflect broad open-source adoption and code auditability · Government and Defense deployment tiers authorized up to DoD Impact Level 6 for classified environments, matching Element's own Sovereign tier ambitions
Loses:Federated communications aren't built on the open Matrix protocol, so cross-organization messaging works differently than Element's decentralized, protocol-standard federation · No published list pricing for Commercial, Government, or Defense tiers, all requiring a sales conversation, the same gap in Element's own Enterprise and Sovereign tiers · Self-hosting the Community Edition adds administration and infrastructure overhead comparable to what self-hosting Element's own Community edition requires
Pros
- Community Edition is free, open-source (MIT license), and self-hostable with no user limit.
- Deployment options span standard cloud hosting to fully air-gapped, classified environments.
- Federated communications let separate Rocket.Chat deployments message across organizational boundaries.
- Extensible via custom and pre-built apps, plus native voice, video, and screen sharing.
Cons
- No published list pricing for any paid tier; every quote requires a sales conversation.
- Self-hosting the Community Edition adds administration and infrastructure overhead compared to SaaS competitors.
- Government/Defense-specific features add complexity that most mainstream business customers won't need.
Pricing: Free — Free Community Edition at $0; Commercial/Government/Defense tiers unpublished (contact sales) vs Element's free AGPL Community edition at $0, with Enterprise/Sovereign also requiring a sales conversation (verified undefined NaN, NaN)