Open Source Software as a Service (SaaS) Apps

Browse 818 Open Source Software as a Service (SaaS) Apps on AlternativeTo with popular options like Free and Paid.

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  1. Bitwarden icon
     1339 likes

    Open-source password manager with AES-256 encryption and device sync. Store and access encrypted logins across platforms like iOS and Android.

    • Password Manager
    • FreemiumOpen Source
    • Mac
    • Windows
    • Linux
    • Online
    • Android
    • iPhone
    • Android Tablet
    • iPad
    • Self-Hosted
    • Apple Watch
    • Snapcraft
    • Microsoft Edge
    • Vivaldi
    • Google Chrome
    • Flathub
    • Microsoft SQL Server
    • Tor Browser
    • Safari
    • F-Droid
    • Software as a Service (SaaS)
    • Flatpak
    • Cloudron
    • Opera
    • Chocolatey
    • Mono
    • Brave
    • Mozilla Firefox
    • Docker
    Bitwarden screenshot 1
    215 alternatives
    4.8
    Excellent173 reviews
  2. ONLYOFFICE icon
     633 likes

    Open-source suite for editing documents, spreadsheets, presentations, forms, and PDF files with co-editing modes, plugin support, AI assistant, and integration across 40+ platforms.

    • Word Processor
    • Free PersonalOpen Source
    • Mac
    • Windows
    • Linux
    • Online
    • Android
    • iPhone
    • Android Tablet
    • HUAWEI AppGallery
    • iPad
    • Self-Hosted
    • AppImageHub
    • Snapcraft
    • Flathub
    • Samsung Galaxy Store
    • Software as a Service (SaaS)
    • Flatpak
    • Cloudron
    ONLYOFFICE screenshot 1
    71 alternatives
    4.1
    Very Good64 reviews
  3. Notesnook icon
     169 likes

    Notesnook is a simple and cross-platform private notes app that keeps your notes organized and synced on your phone, tablet and computer. Take notes, capture ideas, create to-do lists, keep a journal, write your assignments and manage projects, we have got you covered.

    • Note-taking Tool
    • FreemiumOpen Source
    • Mac
    • Windows
    • Linux
    • Online
    • Android
    • iPhone
    • Android Tablet
    • iPad
    • Google Chrome
    • Flathub
    • F-Droid
    • Software as a Service (SaaS)
    • Flatpak
    Notesnook screenshot 1
    292 alternatives
    4.4
    Very Good29 reviews
  4. NextDNS icon
     146 likes

    NextDNS protects you from all kinds of security threats, blocks ads and trackers on websites and in apps and provides a safe and supervised Internet for kids — on all devices and on all networks.

    • Ad Blocker
    • FreemiumOpen Source
    • Mac
    • Windows
    • Linux
    • Online
    • Android
    • iPhone
    • Chrome OS
    • BSD
    • iPad
    • UC Browser
    • Vivaldi
    • Google Chrome
    • UniFi Network
    • Safari
    • Yandex Browser
    • Software as a Service (SaaS)
    • OpenWrt
    • Opera
    • Alpine Linux
    • pfSense
    • Mozilla Firefox
    • DD-WRT
    NextDNS screenshot 1
    139 alternatives
    4.6
    Excellent16 reviews
  5. addy.io icon
     135 likes

    Open-source service offering unlimited anonymous email aliases, encrypted forwarding, spam protection, and anonymous replies to keep your identity private.

    • Disposable Email Service
    • FreemiumOpen Source
    • Online
    • Android
    • iPhone
    • Android Tablet
    • iPad
    • Self-Hosted
    • Microsoft Edge
    • Google Chrome
    • Safari
    • F-Droid
    • Software as a Service (SaaS)
    • Mozilla Firefox
    Manage aliases from the dashboard
    109 alternatives
    4.7
    Excellent16 reviews
  6. ownCloud icon
     863 likes

    Self-hosted platform for secure file sync, sharing, calendar, and contact management with desktop, mobile, web access, and multi-device syncing.

    • Cloud Storage Service
    • FreemiumOpen Source
    • Mac
    • Windows
    • Linux
    • Android
    • iPhone
    • Blackberry
    • Android Tablet
    • iPad
    • Self-Hosted
    • Software as a Service (SaaS)
    • Raspberry Pi
    • Cloudron
    ownCloud screenshot 1
    220 alternatives
    3.4
    Fair8 reviews
  7. CryptPad icon
     167 likes

    CryptPad is a private-by-design alternative to popular office tools and cloud services. All the content stored on CryptPad is encrypted before being sent, which means nobody can access your data unless you give them the keys.

    • Word Processor
    • FreemiumOpen Source
    • Software as a Service (SaaS)
    • Self-Hosted
    • Cloudron
    Instance homepage
    72 alternatives
    4.6
    Excellent21 reviews
  8. Wire icon
     312 likes

    Wire is the most secure collaboration platform featuring messenger, voice, video, conference calls, file-sharing, and external collaboration –all protected by the most secure end-to-end-encryption.

    • Instant Messenger
    • Free PersonalOpen Source
    • Mac
    • Windows
    • Linux
    • Online
    • Android
    • iPhone
    • Android Tablet
    • iPad
    • Self-Hosted
    • F-Droid
    • Software as a Service (SaaS)
    • Flathub
    • Snapcraft
    Wire screenshot 1
    Wire screenshot 2
    Wire screenshot 3
    281 alternatives
    4.1
    Very Good21 reviews
  9. Docmost icon
     43 likes

    Docmost is an open-source collaborative wiki and documentation software. It is an open-source alternative to Confluence and Notion.

    • Note-taking Tool
    • PaidOpen Source
    • Self-Hosted
    • Software as a Service (SaaS)
    • Docker
    Docmost screenshot 1
    87 alternatives
  10. Cryptee icon
     101 likes

    Cryptee is a safety and privacy focused, encrypted and cross-platform personal data storage service. You can write personal documents, notes, journals, store photos (including raw photos from DSLR cameras) and all sorts of other files.

    Cryptee screenshot 1
    70 alternatives
    4.4
    Very Good18 reviews
  11. Mattermost icon
     253 likes

    Mattermost is a secure, open source platform for communication, collaboration, and workflow orchestration across tools and teams.

    • Group Chat App
    • PaidOpen Source
    • Mac
    • Windows
    • Linux
    • Online
    • Android
    • iPhone
    • Android Tablet
    • iPad
    • Self-Hosted
    • JavaScript
    • Software as a Service (SaaS)
    • Go (Programming Language)
    • Cloudron
    Mattermost screenshot 1
    130 alternatives
    3.5
    Good11 reviews
  12. Koofr icon
     136 likes

    Koofr is a safe, secure and simple way to store, backup and share your documents, photos, videos and more. It offers up to 10 GB of free safe storage for your files with affordable upgrades and options to connect multiple cloud accounts.

    • Cloud Storage Service
    • FreemiumOpen Source
    • Mac
    • Linux
    • Online
    • Android
    • iPhone
    • Android Tablet
    • Windows Phone
    • iPad
    • Linux Mobile
    • Google Chrome
    • F-Droid
    • Software as a Service (SaaS)
    • Mozilla Firefox
    • Self-Hosted
    • Docker
    • Rust
    • Chromium
    Koofr web app
    193 alternatives
    4.5
    Excellent11 reviews
  13. Taiga.io icon
     300 likes

    Taiga is the easy and intuitive yet powerful agile project management tool for multi-functional teams. Taiga has a best in class Sprint task board, and you can seamlessly migrate to Kanban if needed.

    • Project Management Tool
    • FreemiumOpen Source
    • Online
    • BSD
    • Self-Hosted
    • Django
    • Angular
    • Software as a Service (SaaS)
    • Cloudron
    Taiga.io screenshot 1
    223 alternatives
  14. Teable icon
     46 likes

    Teable is a super fast, real-time, professional, developer friendly, no-code database built on Postgres. It uses a simple, spreadsheet-like interface to create complex enterprise-level database applications.

    • Free PersonalOpen Source
    • Online
    • Self-Hosted
    • Software as a Service (SaaS)
    • Docker
    Teable screenshot 1
    69 alternatives
  15. Rybbit icon
     24 likes

    Rybbit is the modern open source and privacy-friendly alternative to Google Analytics. It takes only a couple of minutes to set up and is super intuitive to use.

    Rybbit screenshot 1
    55 alternatives
  16. Seafile icon
     192 likes

    Seafile is an open-source file management and collaboration platform that goes beyond sync and share, offering extensible metadata, multi-level tagging, flexible file views, and AI-powered organization for smarter teamwork.

    • Cloud Storage Service
    • FreemiumOpen Source
    • Mac
    • Windows
    • Linux
    • Online
    • Android
    • iPhone
    • Android Tablet
    • iPad
    • Self-Hosted
    • Software as a Service (SaaS)
    Seafile screenshot 1
    125 alternatives
    3.6
    Good7 reviews
  17. DeepNotes icon
     44 likes

    DeepNotes is an open source, end-to-end encrypted visual note-taking app with deep page navigation and live collaboration. Create mind maps, diagrams, kanban boards, among others. Infinite nesting of infinite canvases.

    • Note-taking Tool
    • FreemiumOpen Source
    • Mac
    • Windows
    • Linux
    • Online
    • Android
    • iPhone
    • Android Tablet
    • iPad
    • Software as a Service (SaaS)
    Family tree
    80 alternatives
  18. Proton Wallet icon
     26 likes

    Proton Wallet is a self-custody wallet, meaning we use end-to-end encryption to ensure that you are the only one with access to your wallet's encryption keys.

    • Crypto Wallet
    • FreeOpen Source
    • Online
    • Software as a Service (SaaS)
    • Android
    • iPhone
    Proton Wallet screenshot 1
    54 alternatives
  19. Matomo icon
     223 likes

    Self-hosted GPL-licensed analytics with advanced privacy, customizable reports, insights on visitor languages, search keywords, and real-time traffic sources.

    • Web Analytics Service
    • FreemiumOpen Source
    • Online
    • Android
    • iPhone
    • Android Tablet
    • iPad
    • Self-Hosted
    • Software as a Service (SaaS)
    • PHP
    • Cloudron
    • Wordpress
    Matomo screenshot 1
    165 alternatives
    4.8
    Excellent8 reviews
  20. Enterprise-ready on-premise suite with advanced word processing, spreadsheet, and presentation tools, maximizing interoperability and file compatibility.

    • Word Processor
    • FreemiumOpen Source
    • Mac
    • Windows
    • Linux
    • Android
    • iPhone
    • Chrome OS
    • Android Tablet
    • iPad
    • Self-Hosted
    • Software as a Service (SaaS)
    • Cloudron
    • Flathub
    • Flatpak
    Collabora Office Classic screenshot 1
    40 alternatives
  21. VERT.sh icon
     18 likes

    VERT.sh is an online file converter that processes files on your device instead of the cloud. It's blazingly fast, ad-free, and open source.

    • Audio Converter
    • FreeOpen Source
    • Online
    • Self-Hosted
    • Software as a Service (SaaS)
    Landing page (light mode)
    58 alternatives
  22. Baserow icon
     68 likes

    Baserow is the secure, open-source platform for building databases, applications, automations, and AI agents — all without code. Trusted by over 150,000 users, Baserow delivers enterprise-grade security with GDPR, HIPAA, and SOC 2 Type II compliance, plus cloud and self-hosted...

    • Database Management Tool
    • FreemiumOpen Source
    • Online
    • Self-Hosted
    • Kubernetes
    • Software as a Service (SaaS)
    • Cloudron
    • Docker
    • Docker Hub
    Baserow screenshot 1
    50 alternatives
    3.8
    Good10 reviews
  23. Grist icon
     48 likes

    Transform data with an open-source interface using relational databases and Python engines. Collaborate in real-time with custom permissions for security.

    • Spreadsheet App
    • FreemiumOpen Source
    • Mac
    • Windows
    • Linux
    • Online
    • Software as a Service (SaaS)
    Grist screenshot 1
    41 alternatives
    5.0
    Excellent9 reviews
  24. NewsBlur icon
     681 likes

    NewsBlur is a personal news reader that brings people together to talk about the world. It shows you the original site and allows you to read stories directly off the site while keeping track of what you read. It also filters and highlights stories you like and dislike.

    • RSS Reader
    • FreemiumOpen Source
    • Online
    • Android
    • iPhone
    • Android Tablet
    • iPad
    • Kindle Fire
    • Software as a Service (SaaS)
    NewsBlur screenshot 1
    263 alternatives