References

References — 9 free browser-based developer tools including ASCII Table, HTML Entities Reference and CSS Units Reference. Everything runs locally with no signup or uploads, so your data stays private and results are instant.

9 tools

ASCII TableASCII table with all 128 standard characters (0-127) and their decimal, hex, octal, binary and HTML entity values. Search by code or name, and filter control, printable and symbol characters — free in your browser.

HTML Entities ReferenceFree online HTML entities reference listing named and numeric character codes by category, from arrows and currency to math and punctuation. Search any entity and copy its code or symbol.

CSS Units ReferenceCSS units reference for px, em, rem, %, vw, vh, vmin, vmax and ch, grouped by category with clear guidance on when to use each one. Covers absolute and relative units, free in your browser.

Emoji PickerFree online emoji picker to browse and search thousands of emojis by category. Find the right one in seconds and copy it to your clipboard with a single click.

Git CheatsheetGit cheatsheet with searchable commands by category, from branching and merging to rebase, stash and reset. Each entry shows usage and a danger level so you avoid destructive mistakes, free in your browser.

Linux Commands ReferenceLinux commands reference organizing the most-used commands by category — files, processes and networking — with searchable usage examples. Free and instant in your browser.

Keyboard Shortcuts ReferenceFree online keyboard shortcuts reference that organizes the most useful VS Code, Chrome, macOS, and Windows hotkeys by category, searchable for any action.

Semver CheckerSemantic version comparator that compares two semver strings by major, minor and patch and tells you which version is newer. It also reports the type of release change, free and instant in your browser.

Browser Compatibility CheckerBrowser compatibility checker for any CSS, JavaScript, HTML or Web API feature, showing which Chrome, Firefox, Safari and Edge versions support it. Free and instant, so you can pick browser targets with confidence.

How to Use

1
Open the reference you need— ASCII codes and HTML entities, CSS units, Git and Linux commands, editor keyboard shortcuts and emoji each have their own page, so you land on the table rather than on an article.
2
Filter down to the exact entry— The search box narrows the table as you type, which is faster than scrolling a long cheatsheet or reading a manual page.
3
Copy it, then check it is usable— One click copies the character, code or command; the browser compatibility checker tells you where a feature is supported and the semver checker whether a version satisfies a range.

Frequently Asked Questions

Any release that keeps the leftmost non-zero number, so ^1.2.3 accepts 1.9.0 but not 2.0.0, while ~1.2.3 only accepts patches up to 1.2.x. Feed two versions to the Semver Checker and it tells you which is newer and whether the jump is a major, minor or patch change.

Whenever the character appears in HTML text or in an attribute value: an ampersand followed by letters and a semicolon is read as an entity, so a query string like ?a=1&copy=2 silently turns into a copyright symbol. The HTML Entities Reference lists the named, decimal and hex forms, and the entity converter escapes a whole block at once.

rem for font sizes and spacing that should scale with the reader's browser setting, em when a value should follow the element's own font size such as padding inside a button, and vh or vw only where the measurement genuinely relates to the viewport. The CSS Units Reference groups every unit with guidance on where each behaves predictably.