Darkkle

Darkkle is a free, open-source browser extension that gives the Google Sheets web app a true-black, configurable dark theme. It works in Chromium-based browsers such as Chrome and Edge, stores everything locally, and contains no analytics, advertising, or remote code.

Darkkle is maintained by volunteers. The repository owner may be unavailable for extended periods. Support, fixes, compatibility, reviews, and release dates are not guaranteed. Check whether a release is marked Pre-release before installing it.

What Darkkle looks like

A blank Google Sheets spreadsheet with the Darkkle dark theme applied, showing a true-black grid, readable white column letters and row numbers, and a dark toolbar, menu bar, and sheet tab.
Darkkle applies a true-black theme to the spreadsheet grid, the toolbar, the menu bar, and the sheet tabs. Column letters and row numbers stay readable.
The Darkkle settings panel pinned beside a Google Sheets spreadsheet, showing an on and off switch, a live preview table, and Simple Dark and Tinted quick style options.
The settings panel opens pinned beside the spreadsheet. A live preview shows how greys flip while colours you chose yourself stay exactly as you set them. Settings are saved per spreadsheet.
A selected cell range from D7 to E11 in a dark Google Sheets spreadsheet. The column letters D and E and the row numbers 7 to 11 are highlighted in a coordinated green tint, and the labels remain readable against the highlight.
Choosing a theme tint coordinates the selection, the row and column header highlights, the cell lines, and the drawn-border colour together. Selected header labels stay readable against the highlight.

Why a dedicated extension

The Google Sheets grid is drawn on an HTML canvas, not as ordinary styled page elements. Generic dark-mode extensions restyle the page around the grid but cannot recolour what the canvas paints, which leaves an unreadable white sheet inside a dark shell.

Darkkle hooks the canvas drawing operations directly. It recolours the grid, selections, gridlines, and row and column headers, while leaving cell fills and text colours you chose yourself recognisable.

What Darkkle does

Install

  1. Open the Releases page and check whether the release is marked Latest or Pre-release.
  2. Download the Darkkle-v…zip asset — not the repository source archive.
  3. Extract it to a permanent folder.
  4. Open your browser’s extension-management page (chrome://extensions or edge://extensions).
  5. Enable Developer mode.
  6. Choose Load unpacked and select the extracted folder containing manifest.json.
  7. Refresh any spreadsheet tabs that were already open.

Full instructions, including safe upgrades, are in the installation guide.

Privacy and permissions

Darkkle requests only the storage extension permission, plus narrowly scoped access to the spreadsheet web app, its embedded Google companion panels, and Google-hosted static stylesheets.

There is no account, no server operated by the project, and no telemetry. Settings live in your own browser. Because the rendering hook runs inside the page and observes canvas drawing operations, it may encounter rendered text during normal execution, but the project does not retain or transmit that content.

See the privacy summary and the permissions document.

Common questions

See the full FAQ, or how to get dark mode in Google Sheets for background on why this needs a dedicated extension.

Help improve Darkkle

Darkkle is intended to outgrow dependence on one person. Community members can reproduce bugs, test releases, improve accessibility and documentation, propose carefully scoped features, review code, and become trusted triagers or maintainers.

Licence and independence

Darkkle is distributed under the Mozilla Public License 2.0.

Darkkle is independent software. It is not affiliated with, endorsed by, or sponsored by Google. Google Sheets is a trademark of Google LLC and is referenced only to describe compatibility.