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About Sinister

This site lists real English words that you can type with one hand, most common first, then narrows them with filters you chain together. It is Sinister for the left hand and Dexter for the right. Sinister and dexter are Latin for left and right. Sinister came to mean “evil” from an old superstition about the left hand.

Everything runs in your browser. There is no server: the site is static files, and your filters live in the page address, so a link reproduces them.

Which keys count

A hand is a set of keys. QWERTY, Dvorak and Colemak use the standard touch-typing split: the left hand types the five columns on the left (on QWERTY, Q W E R T, A S D F G, Z X C V B) and the right hand types the rest. The “reach column” option drops the index finger’s inner column (T G B on the left and Y H N on the right for QWERTY). Tap keys on the keyboard to choose any set you like; switching hands then mirrors your set. A word is listed only when every letter is in the set. Automated tests check this property for every layout, hand and random key set.

Where the words come from

The word list starts from Open English WordNet 2025 Plus. It keeps single-word entries made only of the letters a to z, and drops abbreviations, element symbols and Roman numerals (such as “ft”, “Eu” and “xiv”). WordNet lists base forms only, so plurals, verb forms and comparatives are added when the frequency list has seen them. That is how “stewardesses” and “aftereffects” appear for the left hand. Words are ranked by wordfreq, so common words come first. The result is 109,519 words. These files are built once, offline, by scripts in the repository. The site never fetches WordNet or wordfreq while you use it.

Filters

By category walks WordNet’s hypernym tree (animal › reptile › snake). A word passes when any of its meanings sits at or below the category. This filter is exact, and it is the ground truth for everything else.

By description takes free text such as “things in a kitchen” or “sounds scary”. The first time you use it, your browser downloads a small embedding model (mxbai-embed-xsmall-v1, 24 MB, from Hugging Face), its runtime (2.7 MB, from jsDelivr), and 4.2 MB of precomputed vectors, one per WordNet meaning. After that, it works offline. Your query never leaves the device. A word scores as its best-matching meaning. The slider sets the minimum similarity, and results are ordered from most to least similar. On 10 category names, an average of 71% of the top 30 words were true members of the category (precision@30). This filter is approximate. Use a category when you need an exact list. The design record has the measurements.

Latin names

The “Include Latin genus names” option loads 244,648 genus names (1.5 MB) from the GBIF Backbone Taxonomy. The subset is accepted genera that contain at least one accepted species, without viruses and without names that WordNet already has. Genus names are single Latin words, which is what the hand filter matches. Species epithets repeat across genera, and full species names are two words. Genera with more species come first. Each genus is filed under WordNet’s matching category, such as “reptile genus”, so the category filter reaches it too.

Privacy

The site counts page views with Umami, which sets no cookies. Nothing you type is sent anywhere. The only other requests are the data files above, made when a feature first needs them.

Sources and licenses

The word list (words.json) combines WordNet with wordfreq’s ranking, so it is shared under CC BY-SA 4.0. The other data files are shared under CC BY 4.0, and the code under the MIT license. Source code.