Note-taking apps differ in a foundational way that isn't always obvious from a features list: where the actual data lives and how it gets from one device to another.
Local-first vs. cloud-synced storage
Cloud-synced apps store notes primarily on the company's servers, syncing automatically across devices and making sharing and real-time collaboration straightforward — but access depends on that company's continued existence and service, and export options vary in how easily notes can be moved elsewhere later. Local-first apps store notes as files directly on your own device, with syncing (if offered) layered on top of that local storage rather than being the primary copy — generally offering more control and longevity independent of any one company, at the cost of sync sometimes being less seamless or requiring separate setup.
Neither approach is universally better — cloud-synced apps generally offer smoother real-time collaboration and easier setup; local-first apps offer more control over your own data and less dependency on one company's continued operation.
Plain text vs. proprietary formats affects long-term portability
Some note apps store content in an open, plain-text-based format (like Markdown) that can be opened, read, and edited by many other applications, even if the original app were discontinued entirely. Others use a proprietary format specific to that app, making the notes harder to move elsewhere or access if that particular app or company stopped being maintained. For notes intended to last years, checking what format is used underneath the app's interface is a genuinely relevant long-term consideration, not just a technical detail.
Search quality varies more than most people expect
For anyone accumulating a large volume of notes over time, search functionality becomes one of the most-used features, and its quality varies significantly between apps — some offer fast, effective full-text search including within attachments or scanned images; others search more narrowly or slowly as the notes collection grows. This is worth testing directly with a reasonably large personal test set before committing long-term to an app, rather than assuming all "search" features perform similarly.
Organizational philosophy differs by app
Some apps use traditional folders and notebooks; others use tags as the primary organizing method; still others use a more freeform, linked-notes structure (sometimes described as a "second brain" or networked-notes approach) where notes connect to each other via links rather than a strict folder hierarchy. These represent genuinely different mental models for organizing information, and personal fit with a specific philosophy matters as much as any individual feature comparison.
The one thing people forget
Actually test the export process before committing significant time to building up notes in a new app — export a reasonably sized sample and confirm the output is genuinely usable elsewhere, since some apps make data technically exportable but in a format that loses formatting, images, or structure in the process, only discovered as a problem after a large, real investment of notes has already accumulated.