Google Chrome 
Microsoft Edge Vivaldi is a feature-rich web browser developed by Vivaldi Technologies AS, a Norwegian company headquartered in Oslo. Founded in 2013 by Jon Stephenson von Tetzchner (co-founder and former CEO of Opera Software) and Tatsuki Tomita, with about 20 former Opera employees joining at launch, Vivaldi released its first stable version on April 6, 2016. The company is employee-owned with approximately 60 employees across 25 nationalities in 7 countries, with no external investors. Vivaldi has approximately 3.1 million active users worldwide.
Built on the Chromium open source engine, Vivaldi includes a built-in ad blocker, tracker blocker, mail client, calendar, feed reader, and extensive UI customization — all without requiring extensions. The browser’s CEO Jon von Tetzchner has publicly vowed to exclude generative AI from the browser. Revenue comes primarily from search engine partnership deals (Google, Bing, DuckDuckGo, Qwant, Ecosia, Startpage, Yahoo) and bookmark/Speed Dial referral partnerships.
While Vivaldi publishes its Chromium modifications under the BSD license and its C++ backend code as open source, the UI layer — which is Vivaldi’s competitive differentiator — is proprietary and distributed in obfuscated form. This means approximately 95% of the code is viewable, but the 5% UI layer that distinguishes Vivaldi is closed source.
Key Features
- Built-in Ad & Tracker Blocker: Three protection levels — no blocking, block trackers only, or block trackers and ads
- Built-in Mail Client: Multi-account email management with unified inbox (Vivaldi Mail)
- Built-in Calendar: Private, integrated calendar
- Built-in Feed Reader: Algorithm-free RSS/Atom feed reader
- End-to-End Encrypted Sync: Cross-device sync with data encrypted on-device before transmission
- Tab Management: Tab stacking, tab tiling, tab grouping
- No AI Integration: CEO has publicly committed to excluding generative AI
- Vivaldi Social: Company-operated Mastodon instance
Privacy Highlights
Vivaldi assigns each installation a unique user ID stored locally. Every 24 hours, the browser sends an HTTPS request to Vivaldi’s servers in Iceland containing the installation ID, browser version, CPU architecture, screen resolution, and time since last message. Vivaldi removes the last octet of the IP address client-side, then performs a local GeoIP lookup to store only approximate country-level location. There is currently no way to opt out of this 24-hour telemetry ping.
Despite this telemetry, Vivaldi states it does not profile user behavior, does not sell data, and does not share data with third parties. Browsing history and downloads are stored locally in encrypted format. The sync service uses end-to-end encryption — data is encrypted on-device before being sent to Vivaldi’s Iceland servers. Crash logs are optional; if enabled, they are processed to extract a stack trace, then deleted, with the trace retained for 60 days.
Vivaldi integrates Google Safe Browsing API and Google DNS by default, creating connections to Google servers. These can be disabled in settings but are enabled out of the box.
Privacy Breakdown
Data Residency (Score: 85 — Confidence: High)
Pros:
- Company headquartered in Oslo, Norway (EU/EEA). Subject to GDPR and Norwegian Data Protection Authority (Datatilsynet).
- Servers located at Hringdu data centers in Iceland (EEA).
- Employee-owned company with no external investors. Norwegian data protection laws exceed GDPR requirements.
Cons:
- CloudFlare (US company) used as proxy for vivaldi.com.
- Google Safe Browsing API and Google DNS enabled by default — creating connections to US infrastructure.
- Search engine partnerships route queries through partner infrastructure (Google, Bing, etc.).
Open Source (Score: 40 — Confidence: High)
Pros:
- Built on Chromium (open source, BSD license). Approximately 92% of code is Chromium open source.
- All Chromium modifications published under BSD license at vivaldi.com/source.
- C++ feature backend code (ad blocker, notes, etc.) published as open source (approximately 3% of codebase).
Cons:
- UI layer (approximately 5% of codebase) is proprietary and distributed obfuscated (minified HTML/CSS/JS with one-letter variables).
- Cannot be classified as FOSS/FLOSS due to the proprietary UI.
- Obfuscated UI code makes independent security audits difficult.
Privacy Policy (Score: 65 — Confidence: Medium)
Pros:
- Clear privacy policy documenting data practices. GDPR compliant with full user rights support.
- Data minimization — only approximate country-level location derived from IP (last octet removed).
- Crash logs optional and automatically deleted after processing. Stack traces retained 60 days maximum.
Cons:
- Mandatory 24-hour telemetry ping with unique installation ID — no opt-out available.
- IP anonymization removes only last octet — remaining three octets still allow reasonably accurate location.
- Google Safe Browsing API enabled by default.
- Not recommended by Privacy Guides due to proprietary UI and telemetry concerns.
Trackers (Score: 60 — Confidence: Medium)
Pros:
- No third-party advertising trackers or ads in the browser itself.
- Built-in ad and tracker blocker available at three protection levels.
- End-to-end encrypted sync service.
Cons:
- Mandatory 24-hour telemetry ping with unique installation ID (no opt-out).
- Google Safe Browsing API enabled by default — sends data to Google.
- Google DNS enabled by default.
- Limited anti-fingerprinting — shares hardware details (graphics card, CPU cores, RAM, color depth, Bluetooth info).
- One privacy study ranked Vivaldi as third-worst browser for privacy (methodology disputed).
Terms of Service (Score: 72 — Confidence: High)
Pros:
- Users can delete accounts and data anytime. GDPR rights respected.
- No user content ownership claims. Data retention kept to minimum necessary.
- IP addresses anonymized. No data selling.
Cons:
- Account can be terminated without explanation or warning.
- Broad liability disclaimers.
Controversies
The most discussed privacy concern is Vivaldi’s mandatory 24-hour telemetry ping with a unique encrypted installation ID that cannot be opted out of. Vivaldi states this is necessary for counting active users (for partner reporting) and is essential for business survival. Critics argue this is not “strictly necessary” for browser functionality. [1]
CEO Jon von Tetzchner accused Google of retaliating against Vivaldi by suspending its AdWords account after publicly criticizing Google’s privacy practices. Google denied any connection between the criticism and the account suspension. [2]
Vivaldi is not listed on Privacy Guides as a recommended browser, primarily due to the proprietary UI code and telemetry concerns. [3] A widely-reported study ranked Vivaldi as the third-worst browser for privacy, though Vivaldi disputed the methodology. [4]
