About Bookmarklet.io
A transparent account of the tools, code-processing model, security limits, editorial standards, ownership, and correction process.
Purpose
Bookmarklet.io is a focused toolkit for turning readable JavaScript into a bookmark URL, decoding existing bookmarklets, inspecting browser capabilities without execution, testing DOM changes in an isolated local document, and learning the practical limits of javascript: URLs. The site favors visible source and narrow tools over opaque “one-click” promises.
How code is processed
The converter strips an existing prefix when needed, optionally wraps source in an immediately invoked function, uses Terser for standards-aware minification, percent-encodes the result, and adds the javascript: prefix. Decoding reverses the URL encoding so the source can be reviewed.
Converter, decoder, inspector, and fixture input is processed in the browser. Bookmarklet.io does not intentionally upload or store the code entered in those tools. Page analytics and advertising are described separately in the privacy policy.
Security model and limits
The inspector performs static pattern checks. It does not run code and cannot certify a bookmarklet as safe. The local fixture runs code in a sandboxed, unique-origin iframe that restricts request APIs, external resources, forms, popups, top navigation, and downloads. A script can still replace its own preview, so the fixture is for local DOM tests with code you understand—not hostile-code analysis or simulation of every real site.
Browser behavior changes with page origin, Content Security Policy, CORS, permission state, and browser implementation. The documentation distinguishes what a bookmarklet may attempt from what a particular page will allow. Unknown code should never be tested on a signed-in or sensitive page.
Ownership and maintenance
John Sorrentino created and maintains Bookmarklet.io as part of a collection of focused browser utilities. The source is published on GitHub. Tool behavior, documentation claims, and example code are reviewed together when the converter, inspector, sandbox, or library changes.
Corrections
If a browser claim, decoded result, generated URL, inspector finding, or example is wrong, use the contact page and include the page, browser, input, expected result, and actual result. Reports that can be reproduced take priority over adding more examples.