Heynote is a free, open-source scratchpad app from Swedish developer Jonatan Heyman that turns one persistent text buffer into a block-based playground for code snippets, JSON responses, half-written Slack messages and napkin math. We rate it 86/100 — the best dedicated scratchpad on the market for developers who want zero ceremony and have outgrown ~/scratch.txt, with the caveat that there is no mobile app and no built-in sync.

What is Heynote?

Heynote was created by Jonatan Heyman — the Stockholm-based engineer behind the popular load-testing framework Locust — and the first commit landed on December 28, 2022. He launched it on Hacker News just before Christmas 2023, the post hit 1,000+ upvotes, and the project has steadily grown to 5,200+ GitHub stars and 267 forks while staying a single-maintainer side project. The latest stable release is 2.8.2 (February 11, 2026), with a 2.9.0-beta available for early testers.

The core idea is brutally simple: instead of opening a new Notion page, a fresh tab in VS Code, or another untitled.txt every time you want to think for a moment, Heynote gives you one always-open buffer divided into colored blocks. Each block has its own language — JSON, Markdown, JavaScript, Python, SQL, YAML — with proper CodeMirror syntax highlighting and one-keystroke auto-format. It is closer to a long-running whiteboard than a notes app.

Heynote main interface showing block-based scratchpad with multiple syntax-highlighted blocks — Heynote’s default view: one persistent buffer divided into language-aware blocks. `Cmd+Enter` creates a new block, `Cmd+A` selects only the current block.

Key Features of Heynote

Block-based persistent buffer: One always-on text buffer divided into independent blocks. Cmd/Ctrl+Enter creates a new block, Cmd/Ctrl+A selects only the current block instead of the whole document — a small detail that fundamentally changes how you write quick notes.
32+ language modes with auto-format: Each block can be set to JavaScript, JSON, Markdown, Python, SQL, YAML, TOML, Rust, Go, Ruby, PHP, TypeScript, Mermaid, Shell, and more, with full syntax highlighting and one-key Prettier-powered auto-format. Language can also be auto-detected.
Math & calculator blocks: Powered by Math.js. You can write 23 * 60 + 45 minutes to hours, define variables, run unit conversions and even live currency conversions. Easily the most-loved feature for engineers who keep a calculator open all day.
Multiple buffers in tabs: Beyond the default Scratch buffer, Cmd/Ctrl+N creates a new buffer, Cmd/Ctrl+S moves the current block into a new buffer, and Cmd/Ctrl+P jumps between them. Buffers map to plain files on disk and can be organized into folders.
Inline images: Paste from clipboard or drag-and-drop image files directly into a buffer. Images can be selected, resized in-place, and copied back to the system clipboard.
Global hotkey: Bind a system-wide shortcut to summon Heynote from anywhere — effectively a code-aware Spotlight pad.
Multi-cursor editing, spellcheck, dark/light themes, and Emacs-style key bindings: All optional, all configurable per-buffer.
Plain-file storage: Buffers are stored as files on your disk. You point your own Dropbox, iCloud, Syncthing or git repository at the folder if you want sync — there is no Heynote cloud.

Heynote math block performing live calculations and unit conversions — Math blocks evaluate inline as you type, support variables, functions and live currency conversions — the closest thing to Soulver inside a code editor.

What Users Say About Heynote

Sentiment is unusually warm for a category as crowded as note-taking. The original Show HN thread hit 1,000+ points and the most-quoted comments call out the math/calculator block as “the killer feature I didn’t know I needed” and praise the explicit refusal to add bloat. Reddit threads in r/programming and r/webdev consistently describe Heynote as a permanent replacement for half-deleted scratch.txt files, Apple Notes, and Sticky Notes on Windows.

The honest criticism is consistent and worth knowing before you switch. There is no mobile app — and the maintainer has explicitly closed mobile feature requests as out of scope. There is no built-in sync; you have to point a third-party sync tool at the buffer folder. There is no real-time collaboration, so it is a single-user tool by design. And while the Electron shell is fast enough on modern hardware, users on older laptops occasionally complain about the 200–300 MB memory footprint that comes with Chromium.

Heynote Pricing

Heynote is 100% free and open source. There is no paid tier, no subscription, no “Pro” upsell and no telemetry. The license is a permissive custom license that allows personal and internal commercial use; the code lives on GitHub.

Plan	Price	What you get
Heynote	$0 forever	Every feature, all platforms, no limits, no account required

Who Should Use Heynote?

Best for: Working developers, SREs, data engineers, and technical PMs who want a single always-open scratch buffer with code-aware highlighting, fast launching, and a built-in calculator. Particularly valuable if you currently juggle a TextEdit window, a calculator app, and an “untitled-1” tab in VS Code.

Not ideal for: Teams that need real-time collaboration (use Notion or AFFiNE), users who need a mobile companion (use Obsidian or Capacities), or anyone storing client-confidential notes — there is no encryption layer beyond your filesystem.

Pros and Cons

Pros:

Free, open source, no account, no telemetry — rare for an actively maintained 5,000-star app
The math block alone replaces Soulver, PCalc and your iOS calculator widget
Plain-file storage means you own your data and can sync however you like
Fast launch and instant block-switching once it’s in memory
Native packages for macOS (universal/arm64/x64), Windows and Linux (AppImage + Snap)

Cons:

No mobile app — explicitly out of scope
No native sync; you must wire up Dropbox, iCloud, Syncthing or git yourself
No collaboration features; this is a single-user tool
Electron-based, so 200–300 MB resident memory is the floor
Slow release cadence (single-maintainer project) — the 2.9 line has been in beta for months

Alternatives to Heynote

The closest alternatives in the “developer scratchpad” niche are Edna (a web-based fork-style alternative with cloud sync), Boop (macOS-only, transformation-focused), and Notable (a more traditional Markdown notes app). On the heavier end, Obsidian and Capacities are full PKM systems that overlap with Heynote but trade simplicity for power.

Verdict: Is Heynote Worth It?

Yes — if you are a developer or technical user who already keeps a stray text file open all day, Heynote is the polished version of that habit and it costs nothing. The math block, the language-aware blocks and the global hotkey will earn back their five-minute setup within a day. Subtract points only if you genuinely need mobile, sync, or collaboration — in which case look at Obsidian, Capacities, or a hosted note app instead. We rate Heynote 86/100.

Frequently Asked Questions

Is Heynote free?: Yes. Heynote is 100% free and open source under a permissive license. There are no paid tiers, no accounts, and no telemetry. You can download it from heynote.com or build from the source on GitHub.
What platforms does Heynote support?: Heynote runs on macOS (Universal, Apple Silicon, and Intel), Windows, and Linux (AppImage and Snap). There is no iOS, Android, or web version.
How does Heynote compare to Obsidian?: Heynote is a dedicated scratchpad — one persistent buffer with code-aware blocks. Obsidian is a full personal knowledge management system with linking, plugins, and graph views. If you want to think for 30 seconds, Heynote is faster; if you want a second brain, Obsidian is more capable.
Is Heynote open source?: Yes. The full source code is available at github.com/heyman/heynote, with 5,200+ stars and active issue tracking. The project is maintained primarily by its creator, Jonatan Heyman.
Does Heynote sync between devices?: Not natively. Heynote stores buffers as plain files on disk, so you can sync them by pointing Dropbox, iCloud Drive, Syncthing, or a git repository at the buffer folder. There is no Heynote cloud.
Can Heynote do calculations?: Yes. Heynote has a dedicated Math block powered by Math.js that evaluates expressions inline, supports variables and functions, and performs unit and currency conversions — effectively a built-in Soulver/PCalc.

#note-taking

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