The main kanji part or component in a character. This differs from components which can occur multiple times in a character.
Most "radical searches" on websites and apps are actually component searches. Use the Components section of this page for a similar experience.
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Kanji parts that are found in many characters. Components in characters are often not shaped exactly like the original component. They may be stetched, squished, or otherwise distorted.

Identifies kanji based on components present in each corner of the character. Not every corner component is strictly in the corner. (More information)

Identifies kanji based on a pattern, the stroke order within the shaded or dark part of the pattern, and the stroke order within the unshaded or light part of the pattern.
Kanji which can be split vertically (left-right) are pattern 1, kanji which can be split horizontally (top-bottom) use pattern 2, kanji which are contained in an enclosure use pattern 3, and kanji which cannot be split use pattern 4.
Stroke count can be an imperfect measurement due to discrepancies in how characters are written. The ± option allows matching all characters with a stroke order within the specified range around the specified stroke order.
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Narrows down the search to kanji present in possible words.
For example, entering 　 し 　 す allows limiting to kanji that are contained in words which have し as the second character and す as the fourth character.
Filtering applies to words longer than four characters but only the first four characters may be filtered. Do not input characters that are part of conjugations or inflections.
Only one character may be input in each input box. Both kanji and hiragana are accepted. Katakana is not accepted. A kana IME is built into the page to convert romaji to hiragana.

Only show kanji with stroke counts greater than, equal to, and/or less than the specified numbers.