Open-source note-taking, honestly reviewed. No marketing fluff, just what you get.

TL;DR

What it is: A free, open-source (AGPL-3.0), PWA-based note-taking app focused on simplicity, cross-platform access, and end-to-end encryption [README].
Who it’s for: Solo users who want a lightweight, private, Markdown-capable alternative to Google Keep or Apple Notes — and don’t need the complexity of Obsidian, Notion, or Logseq.
Cost savings: OpenNotas is completely free. No paid tiers, no usage caps, no per-seat pricing. The only cost is optional self-hosting if you configure your own sync backend [website FAQ].
Key strength: Zero-cost, E2EE by default, genuinely simple. If you’ve been paying for Notesnook or bumping against Notion’s collaboration pricing for personal notes, OpenNotas costs nothing [README][website].
Key weakness: This is a solo developer’s personal project with 167 GitHub stars, an explicit request not to submit feature PRs, and sync that requires manual “Adapter” configuration. It is not a product you’d bet a team’s workflow on.

What is OpenNotas

OpenNotas is a personal note-taking app built as a Progressive Web Application (PWA). The developer — a full-time programmer who runs a coding tutorial blog — built it in just over a month to scratch their own itch for a cross-platform, privacy-focused note-taking tool [README]. That origin story is worth keeping in mind: this is not a VC-backed product with a roadmap and a support team. It’s an honest, functional, open-sourced personal tool.

The pitch is “simple, lightweight, cross-platform,” and those three words describe it accurately. Notes are written in Markdown. The app installs as a PWA on any device — desktop, mobile, Windows, macOS, Linux, Android, iOS — through the browser, without native app store downloads [README][website]. Note data is encrypted with AES before it leaves your device, so if you’re using any sync backend, the server only ever sees ciphertext [README].

The GitHub description calls it “A Simple, Lightweight, Cross-Platform Personal Note-Taking Application” and explicitly adds “Focusing on Security and Completely Free.” That last clause is the honest pitch: where Notesnook charges for its premium tier, where Standard Notes charges for extended features, OpenNotas gives you E2EE and multi-platform sync for free.

As of this review: 167 GitHub stars. One active developer. No native mobile apps — PWA only [README][website].

Why people choose it

There’s no shortage of reviews of competing tools in this space, but I couldn’t find third-party reviews that specifically benchmark OpenNotas. What the general note-taking discourse does tell us is what drives people toward lightweight open-source alternatives — and OpenNotas hits those notes squarely.

The XDA Developers piece on Memos [2] describes exactly the audience OpenNotas is aiming for: people who replaced Google Keep with something self-hosted because they want “one click to start writing” and all notes visible without navigating folders. The writer explicitly says: “I have very few expectations from a note-taking app. Taking a new note should be one click away.” OpenNotas’s homepage echoes this: “Just a tap and you can start writing notes immediately” [website].

Jessica Journals’ note-taking chronicle [3] tracks a progression through Octarine → Memos → Blinko while searching for something that works frictionlessly on both desktop and mobile. The same pattern — jumping between tools because none quite fits — shows up constantly in self-hosted note-taking communities. OpenNotas’s PWA approach is a direct response: install once via browser, use everywhere, no app store dependencies.

The Medium roundup of open-source note apps [1] focuses on apps with larger communities (Notesnook, Obsidian, Logseq) and explicitly excludes tools with steeper learning curves. OpenNotas exists further down that spectrum — fewer features, but also less to learn.

The honest synthesis: people who land on OpenNotas are usually looking for something smaller than Joplin, simpler than Obsidian, cheaper than Notesnook Premium, and more private than Google Keep. It fits that slot cleanly if your requirements are modest.

Features

Based on the README and website:

Core editing:

Markdown support with open-source editor tooling [README]
Clean, minimal interface — by design, not by accident [website]
Offline use: notes stored locally in browser persistent storage, synced when internet returns [website FAQ]

Cross-platform:

PWA installable on Windows, macOS, Linux, iOS, Android [README][website]
No separate native app downloads required — browser is the runtime
Web version available at https://opennotas.io for trying without installation [website]

Privacy and sync:

End-to-end encryption using AES — note data is encrypted before leaving your device and before reaching any sync server [README][website]
You hold your own secret key; the sync server cannot read your notes [website FAQ]
Sync via “Adapter” configuration — plugs into your own backend (exact supported backends require checking the docs at https://docs.opennotas.io/advanced/sync-flow)

What it doesn’t have:

No backlinks or bidirectional note linking (that’s Obsidian/Logseq territory)
No notebooks, tags, or hierarchical folder structure mentioned in the docs
No attachment support documented in the core feature set
No collaboration or shared notes
No API
No native mobile apps — PWA only

The missing features list isn’t a failure — they’re deliberate exclusions. The README’s philosophy is “simplicity in usage” for people who need to “quickly and reliably jot down their notes in text format” [README]. If you need more than that, this isn’t your tool.

Pricing: SaaS vs self-hosted math

OpenNotas: Free. No tiers. No paid plans. Completely open source under AGPL-3.0 [README][website FAQ].

The cost comparison here is simpler than most self-hosted tools because there’s no hosted paid tier to compare against. The meaningful comparison is against services people are currently paying for:

Service	Personal plan cost	E2EE	Self-hostable
OpenNotas	$0	Yes (AES)	Yes (AGPL)
Notesnook	$4.49–$5.99/mo	Yes	No (cloud-only)
Standard Notes	$3.33–$9.99/mo for extended	Yes	Yes (complex)
Notion Personal	Free (limited) / $10/mo	No	No
Evernote	$10.83–$14.99/mo	No	No
Bear	$2.99/mo	No	No (iOS/macOS only)

If you’re paying $4–$10/mo for Notesnook or Standard Notes primarily for E2EE personal notes across devices, OpenNotas is a free alternative worth evaluating. Over a year that’s $48–$120 back in your pocket.

If you’re on Notion’s paid tier for personal use, the comparison is less direct — OpenNotas doesn’t do databases, embeds, or collaborative documents. But for pure text notes with privacy, it’s a substantial downgrade in cost with no downgrade in the core use case.

Self-hosting cost: Optional. The PWA at https://opennotas.io is the free hosted version. If you want your own sync backend, you’d need a VPS (starting around $3–6/mo) and time to configure the Adapter. Data not available on exactly which backend protocols the Adapter supports — check the docs at https://docs.opennotas.io.

Deployment reality check

OpenNotas is unusual in this review category because you don’t need to self-host it to use it privately. The E2EE means the hosted version at opennotas.io is already private by design — the server sees only encrypted blobs [website FAQ]. You can install the PWA from the hosted URL and get full functionality without touching a VPS.

If you want to self-host, the README directs you to the docs at https://docs.opennotas.io/started/install. The README doesn’t include a quick Docker Compose snippet or one-liner install, which is a signal that setup isn’t as frictionless as, say, Memos or Joplin Server.

Browser storage caveat. This is the deployment gotcha worth calling out explicitly: “Data is stored in the persistent memory of the browser you use to install OpenNotas. Therefore, data is only lost when you clear the cache or uninstall the OpenNotas app or the browser.” [website FAQ]. This means clearing your browser cache, reinstalling your OS, or switching browsers can destroy your local notes if you haven’t configured sync. For a note-taking tool you rely on, setting up the Adapter sync is not optional — it’s the only backup.

Solo developer sustainability. The README includes this: “As a full-time programmer and programming tutorial blogger, I have a lot on my plate. Due to time constraints, I kindly request that you temporarily refrain from submitting Pull requests for new features or expect delays in response to Pull requests.” [README]. This is an honest and commendable disclosure. It also means: if you hit a bug or need a feature, you may wait a long time. The project has no stated contributors beyond the original author, and 167 stars over what appears to be roughly a year of activity is a small community.

Pros and cons

Pros

Genuinely free, no bait-and-switch. No freemium gate, no usage limit, no “Pro” tier waiting to be introduced. AGPL-3.0 licensed [README][website FAQ].
E2EE by default. AES encryption happens client-side before any data touches a server. Most paid competitors charge extra for this [README][website].
Cross-platform without native app fragmentation. PWA on every OS means one install path, one codebase, consistent experience [README].
Markdown support. Standard format means you own your notes — you can read them anywhere, not just inside OpenNotas [README].
Offline-capable. Works without internet; syncs when reconnected [website].
Honest scope. The developer didn’t try to build Notion. It does one thing (text notes with E2EE and sync) and doesn’t add complexity for its own sake.

Cons

Solo developer, low activity. 167 stars, explicit PR slowdown notice, no stated contributor base [README]. Long-term maintenance is uncertain.
Browser storage as primary data store. Your notes live in browser cache by default. Clearing cache = data loss if sync isn’t configured [website FAQ]. This is a non-obvious footgun for new users.
Sync requires manual configuration. No out-of-the-box sync that “just works” — you configure an Adapter [README]. What backends are supported is unclear without reading the full docs.
No folder/tag/notebook organization. The feature set is intentionally minimal, which means no organizational structure for users with more than a few dozen notes [README].
No attachment support documented. Images, files, and media aren’t listed as features. Text-only [README].
No native mobile apps. PWA-only means you’re at the mercy of browser PWA behavior, which varies by platform and can be less reliable than a true native app, particularly on iOS [README][website].
No API. Programmatic access, webhooks, or integrations with other tools are not available [README].
AGPL-3.0 has commercial restrictions. If you plan to embed OpenNotas in a commercial product, AGPL requires you to open-source your modifications. Not an issue for personal use, but worth knowing [README].

Who should use this / who shouldn’t

Use OpenNotas if:

You’re a solo user looking for a private, free alternative to Google Keep, Bear, or Apple Notes with E2EE.
You’re currently paying for Notesnook or Standard Notes primarily for E2EE text notes across devices — this replaces that at $0.
You value simplicity over power: you want to type a note and find it later, not build a knowledge graph.
You’re comfortable with PWA installs and understand the browser-storage caveat.
You want to try it immediately with zero setup via the hosted web version.

Don’t use OpenNotas if:

You need backlinks, bidirectional notes, or a personal knowledge base structure. Use Obsidian (with local sync) or Logseq.
You need native mobile apps with reliable offline behavior and background sync on iOS. Use Joplin or Standard Notes.
You’re setting up notes for a team or need any collaboration features. Use Notion or Affine.
You need attachment support — images, PDFs, voice memos. Use Joplin or Notesnook.
You need active community support or fast bug fixes. The solo-developer status and explicit PR slowdown notice are disqualifying for critical workflows.
You’re evaluating this for an organization that needs vendor support SLAs.

Alternatives worth considering

Joplin — The most battle-tested open-source Markdown note-taking app. Native apps for every platform, E2EE sync to your own WebDAV/S3/Nextcloud, attachment support, notebook organization, and a large community. More complex to set up, but more capable and reliable for long-term use. Free.

Memos — A self-hosted microblogging-style note app that XDA Developers called their new favorite way to take notes [2]. Simpler than Joplin but focused on quick-capture, similar to Twitter for notes. Has a native Android app (MoeMemos), and 33k+ GitHub stars means active development.

Standard Notes — E2EE note-taking app with native apps, a free tier covering core features, and a paid extended tier for rich editors. More polished product than OpenNotas, but the extended features cost $3–$10/mo.

Notesnook — The Evernote-shaped private alternative that Medium reviewer Danielpourasgharian calls underrated [1]. Open source, E2EE, good mobile apps, notebooks and tags, Markdown support. Paid tier for full features.

Obsidian — Not open source in the traditional sense (free for personal use, proprietary binary), but the dominant choice for Markdown-based personal knowledge bases. Local files as storage, plugin ecosystem, bidirectional links. Very different use case from OpenNotas — more complex, more powerful.

Blinko — A newer self-hosted option combining a quick-capture flow with longer-form notes, as covered in Jessica Journals [3]. Still maturing but active development.

For a non-technical user escaping Notesnook or Standard Notes billing, the realistic shortlist is OpenNotas vs Joplin. Pick OpenNotas if you want the absolute minimum setup and don’t need attachments or folders. Pick Joplin if you need a native app, attachment support, and confidence in long-term project health.

Bottom line

OpenNotas delivers exactly what it advertises: a simple, free, E2EE Markdown note-taking app that runs everywhere via PWA. For users currently paying $5–$10/mo for an encrypted personal notes app, it’s a legitimate free replacement — and the hosted version at opennotas.io means you get E2EE without running a server. The trade-offs are real and worth naming plainly: a solo developer who has asked the community to slow down contributions, 167 GitHub stars (small for infrastructure you depend on), sync that requires configuration, and browser-local storage that will silently eat your notes if you clear cache without a backup. If your note-taking needs are genuinely minimal — quick text notes, Markdown, privacy — OpenNotas is honest and capable. If you need anything more, Joplin or Memos will serve you better, and both have the community depth to still be around in two years.