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Developer Assistance Tools

Getting started

Developer Assistance Tools (CelesBox) is a suite of 37 developer utilities that runs entirely in the browser. There is no backend and no account. Every tool does its work on your machine, and no tool input ever leaves the browser. It is a static site. The online version at celesbox.com counts anonymous page views with Cloudflare Web Analytics (no cookies, no personal data); the offline and self-hosted versions contain no analytics. See Security and privacy.

Opening a tool

Section titled “Opening a tool”

The home page shows the tool catalogue.

  • Type in the Find a tool search box to narrow the list.
  • Use the category tabs to jump to a group of tools. Collapse all folds the groups.
  • Select a tool’s card to open it.
  • Tools you have pinned appear in a Favourites block at the top of the page, with a Clear all button to unpin them.

The tools are organised into seven categories: data, text, API, security, media, diagrams and dev. See the tools overview for a description of each.

Tool addresses

Section titled “Tool addresses”

Each tool has a clean address with no .html ending, made of its category and name. For example, the Password Generator is at /tools/security/password. Older addresses that still end in .html redirect to the clean paths, so existing bookmarks keep working.

Your work stays in the browser

Section titled “Your work stays in the browser”

Files you open, text you paste and anything you generate are handled by the page itself. Some tools keep a draft in this browser so that you can come back to it. Drafts and notes are kept in local storage, and opened files and full-editor diagrams in IndexedDB. The Settings page has a Clear saved data button that erases both.

Settings

Section titled “Settings”

The Settings page applies to every page on the site. It includes the colour theme and accent colour, where a tool’s toolbar sits, and a choice of which page opens as the home page (the tool catalogue or a start page).

Offline and self-hosted use

Section titled “Offline and self-hosted use”

The public site does not install an offline copy in the browser. If you need the tools on a network without internet access, or want to host them yourself, a self-hosted package and a container image are available. See Self-hosting.