Online Code Editor
Pick a language mode, edit with Ace highlighting, then download the file. Runs in your browser—no install or account.
Completions appear as you type; press Ctrl+Space to open the list. Tab expands snippets where available. Find: Ctrl+F (Cmd+F on Mac). Format: toolbar button or Ctrl+Shift+B for supported languages.
Choose editor font size in pixels
Open a language from the sidebar to load Ace with the matching highlighter, find/replace, theme controls, and download. Each mode has its own URL (for example /code-editor/json or /code-editor/sql) so you can bookmark or share a specific editor.
Use the hub to jump between markup, query, config, and scripting modes during a review. Samples below are starters—language pages add syntax notes and FAQs.
Best for short tasks: a snippet from a ticket, a config tweak before commit, classroom examples, or editing a file on a machine where you do not want to install an IDE.
Not a substitute for production builds, secret-bearing repos, or long debug sessions—keep those in your normal toolchain.
Open a language mode, paste or type in the Ace buffer, use find/replace and theme/font controls, then download when ready. Theme choices may stick in local storage on this device—it is not a cloud project.
Editing stays in your browser for normal use (no account required). Do not paste production secrets; save important work to your own repo or encrypted store.
Starters for common modes. Open the language page for more samples and syntax notes, or copy these straight into the hub editor after you switch mode.
JavaScript module
export function pick(obj, keys) {
return Object.fromEntries(keys.map((k) => [k, obj[k]]));
}SQL probe
SELECT id, status
FROM jobs
WHERE status = 'queued'
ORDER BY created_at
LIMIT 20;HTML shell
<!doctype html>
<html lang="en">
<body><main><h1>Preview</h1></main></body>
</html>YAML service
services:
web:
image: nginx:1.27
ports:
- '8080:80'- Does Code run on ConversionTab servers?
- No. Download the file and run it in your usual compiler or runtime. Editing here does not execute Code on our servers.
- Is my code uploaded while I type?
- Normal editing stays in the browser. You do not need an account to draft or download.
- Can I change theme and font size?
- Yes—use the toolbar above the editor. Preferences can persist in local storage on this device.
- When should I use an IDE instead?
- Use your IDE for large projects, debugging, secrets, and production builds. This page is for short drafts and reviews.