Translation guide
Describes handwriting, print, or text that is impossible or very difficult to read due to poor formation, damage, or obscurity.
The learner wants to say that someone's handwriting, a note, or printed text is impossible to decipher.
The most common and natural way to say something is illegible. Literally 'cannot read'. Works for handwriting, print, or any text.
彼の字は読めない。
His handwriting is illegible.
このメモ、読めないよ。
I can't read this note.
More formal/literary. Means 'cannot decipher' or 'cannot make out'. Often used for old documents or bad handwriting.
古文書は判読できない。
The ancient document is illegible.
Very formal, often used in technical contexts like cryptography or severely damaged texts. Means 'undecipherable'.
その碑文は解読不能だ。
The inscription is illegible.
The learner wants to describe text that is illegible because it's faded, smudged, covered, or too small.
Specifically for text that has faded or blurred. 'Kasureru' means to become faint or blurred.
印刷がかすれて読めない。
The print is faded and illegible.
For text that has bled or smudged, e.g., from water. 'Nijimu' means to blur or run.
インクがにじんで読めない。
The ink has smudged and is illegible.
When text is illegible because it's too small.
文字が小さすぎて読めない。
The text is too small to read.
The learner wants an adjective meaning 'illegible' to describe handwriting or a document.
Means 'hard to read'. Covers illegibility as well as difficult content. Very common.
彼の字は読みにくい。
His handwriting is hard to read.
More precise for 'difficult to decipher'. Slightly formal.
このサインは判読しにくい。
This signature is illegible.
There is no single common Japanese adjective that perfectly matches 'illegible'. Using a phrase like 読めない (cannot read) is much more natural than trying to use a rare word like 難読 (nandoku).