01
Transform text without changing context.
Grayslate detects the current document or selection and puts matching transformations first. Format JSON, convert CSV, decode Base64, hash text, clean up lines, and more—all on your machine.
Free and open source · macOS, Windows, Linux
A fast scratchpad for
code, data, and quick thinking.
Paste an API response. Explore a huge CSV. Transform text or capture a thought. Grayslate recognizes your content, suggests relevant transformations, and automatically names and saves each slate—so you can find it again whenever you need it.
Your files stay on your machine. No account. No telemetry.
- 80+
- local transformations
- 40+
- languages recognized
- 200 MB
- maximum file size
- Auto-saved
- named and searchable
Built for the everyday detours
The small jobs, handled.
Grayslate keeps useful developer tools close without turning every quick task into a project.
02
Large CSVs that still feel usable.
Open and explore CSV files with hundreds of thousands of rows in a Rust-backed, virtualized table.
Virtualized rows keep scrolling responsive.
03
Paste it now. Find it later.
Grayslate recognizes the content, chooses a useful filename and extension, and saves every new slate as you type. Browse recent slates or search by name and content whenever you need it again.
More than 40 languages recognized from content.
JSON shortcuts
Right-click to copy a JSON path, key, or value.
Markdown preview
Write and preview Markdown side by side.
Find across line breaks
Search and replace multiline content without leaving the editor.
Local by design
Your scratch data should not need a round trip.
API responses, customer CSVs, tokens, and unfinished ideas stay on your computer. Grayslate does not require an account, cloud upload, or telemetry.
- Local auto-saveNew slates are saved on your machine as you type.
- No accountInstall it and start working.
- Open sourceRead the code and see how it works.
Questions, answered
Before you download.
The short version: it is free, local, auto-saved, and available on macOS, Windows, and Linux.
Is Grayslate free?
Yes. Grayslate is free and open source under the MIT License.
Which platforms are supported?
Grayslate provides desktop builds for macOS, Windows, and Linux.
How is it different from Boop or Notepad++?
Boop is centered on one-off transformations, while Notepad++ is a general-purpose editor. Grayslate is built around persistent scratch work: it recognizes pasted content, suggests relevant transformations, gives each new slate a useful name, auto-saves it, and lets you search for it later. It also includes real file editing and a Rust-backed large-CSV viewer.
Does Grayslate save my work automatically?
New slates are named and saved automatically as you type, and remain available in the library for browsing or search. Files opened from elsewhere on your computer are never overwritten automatically—Grayslate writes changes to those files only when you explicitly choose Save.
Can it handle large files?
Grayslate can open text and CSV files up to 200 MB. CSV table rows are virtualized so hundreds of thousands of rows remain practical to browse.
Why use a desktop app instead of an online formatter?
Your code and data do not need to be uploaded to a third-party formatter. Grayslate performs its transformations locally on your machine.
Ready when you are
Keep the small jobs out of your browser.
Install Grayslate and turn code, data, and quick notes into automatically saved, searchable slates.
macOSApple Silicon + Intel
Install with Homebrew
brew install --cask shriram-ethiraj/grayslate/grayslateAd-hoc signed; macOS may require Open Anyway on first launch.
Windowsx64 + ARM64
Linuxx86_64
Packages currently target x86_64.
Looking for another package or architecture? View all downloads and release notes.