Which To-Do List App Is Safest for Your Data? A Privacy-Focused Review

Introduction

Task management apps have become a core part of daily life for many professionals and students. But the convenience of syncing tasks across devices often comes at a cost: your personal data may be stored on servers you don’t control, shared with third parties, or left vulnerable in a breach. When Wirecutter’s most recent roundup named Todoist, Microsoft To Do, and Things 3 as the top to-do list apps of 2026, the evaluations focused on features and usability. This review takes a different angle: how well do these apps protect your privacy and security?

What happened

Wirecutter, a product review service owned by The New York Times, published its latest comparison of to-do list apps in December 2025. After testing dozens of options, they singled out three winners based on reliability, cross-platform support, and overall user experience. However, their published review does not dive deeply into encryption policies, data sharing practices, or account protection measures. Given the rising number of data breaches and the increasing scrutiny of app permissions, these factors deserve a closer look.

Why it matters

A to-do list app stores more than just errands. It can contain project notes, work deadlines, personal reminders, and sometimes even sensitive information like meeting locations or health appointments. If an app’s security is weak, your data could be exposed to hackers, advertisers, or employees of the app company itself. For anyone using these tools for work or school—where confidentiality may be required—the privacy trade-offs are not trivial.

Moreover, many popular apps rely on cloud sync to keep tasks updated across devices. That means your data travels over the internet and is stored on company servers. Without end-to-end encryption, the app provider (or anyone who compromises their servers) can read your tasks. Understanding which app offers what type of protection is essential before you commit.

What readers can do

Below is a breakdown of the privacy and security stance of each of Wirecutter’s top three picks, based on publicly available documentation and the apps’ own statements. Keep in mind that policies can change, so it’s wise to verify before signing up.

Todoist offers end-to-end encryption only to paying subscribers on its Pro and Business plans. Tasks created on the free tier are encrypted in transit (using HTTPS) and at rest on Todoist’s servers, but the company holds the decryption keys. That means Todoist employees could theoretically access your data. For sensitive tasks, upgrading to a paid plan enables a “zero-knowledge” mode where only you hold the encryption keys. Two-factor authentication is available on all plans, which is a good step for account security.

Microsoft To Do uses standard encryption for data in transit (TLS) and at rest (AES-256) on Microsoft’s servers. However, like most Microsoft consumer services, the company retains the ability to decrypt your data for legitimate purposes (such as compliance or fraud prevention). Microsoft To Do does not offer end-to-end encryption. It also integrates tightly with other Microsoft 365 services, meaning your task data may be processed by additional systems. Two-factor authentication is available if you have a Microsoft account with it enabled.

Things 3 takes a different approach: all your task data is stored locally on your device. Syncing between Apple devices uses iCloud, which employs end-to-end encryption for most data types (Apple’s security whitepaper confirms that iCloud sync for apps using CloudKit includes end-to-end encryption for the user’s data in transit and at rest on Apple’s servers, provided the app developer does not request access to the raw data. Things 3 does not collect your data on its own servers). There is no cloud-based account to hack, though your iCloud account itself remains a potential vector. Two-factor authentication is handled by Apple’s own system. On the downside, Things 3 is available only on Apple platforms.

To choose the right app based on your privacy needs, consider these questions:

  • Do you need to sync sensitive work or personal information across devices? If yes, a zero-knowledge or locally-stored solution is safer. Todoist paid or Things 3 are better options than Microsoft To Do.
  • Do you use multiple platforms (Windows, Android, Linux)? Things 3 is limited to Apple devices. Todoist and Microsoft To Do are cross-platform.
  • Are you comfortable with the app provider having access to your task data? Microsoft and free-tier Todoist both have access. Things 3 does not.
  • Do you already use two-factor authentication on your account? Enable it regardless of which app you choose. Without 2FA, your account is vulnerable even if the app’s encryption is strong.

Practical steps you can take now: Review the privacy policy of your current to-do app. Check whether it offers end-to-end encryption or stores data locally. Turn on two-factor authentication if available. Consider whether you are comfortable with the app’s data sharing practices—some apps may share anonymized task data for analytics or training. And if you regularly store sensitive notes (passwords, financial details), consider using a dedicated secure notes app instead.

Sources

  • Wirecutter, “The 3 Best To-Do List Apps of 2026”, December 2025. (Original review provides app rankings and feature comparisons.)
  • Todoist Security & Privacy pages (includes encryption details and 2FA availability).
  • Microsoft To Do documentation on data protection and encryption (Microsoft Trust Center).
  • Apple Security Whitepaper (for iCloud end-to-end encryption specifics relevant to Things 3).
  • App store descriptions and developer statements for each application.