A worked example
At 18 px and line height 1.6, the line box is 28.8 px before font-specific layout effects.
Spacing lab
Adjust font size, line height, letter spacing and text-column width with a live sample.
YOUR LITTLE WORKBENCH
ON YOUR DEVICE ✦Spacing lab
Try a sample on your device’s installed fonts. Settings remain in this page only; export a JSON recipe before switching tools. No remote font requests.
A little breathing room
A little space changes everything. Good typography helps ideas find their rhythm. Try your own headline, paragraph or a few words in another language. 留一点空间，让文字更好读。
Line box28.8 px
Tracking0 px
Font rendering depends on what is installed. ch is not an exact character count; exported rem headings assume your chosen root reference. Preview in the actual page before use.
THE METHOD / 01
A clear wayfrom start to finish.
Line height is unitless; letter spacing uses em; the column width uses ch with a responsive maximum.
Keep the assumptions clear
ch refers to the font’s zero-glyph advance, not a precise number of characters per line, especially for CJK.
A FEW USEFUL ANSWERS
Good to know.
Are my inputs uploaded?
No. Processing runs locally in your browser. The host still receives normal requests for website pages and assets.
Can I keep my result?
Use the download controls for the current tool or print from your browser. Seating plans, flashcards and document drafts autosave in this browser; see the privacy page.
Do I need an account?
No sign-up, paid API or subscription is required. Both languages use the same tools. English always opens at the root address.
LETTERKIND / TOOLKIT
A little help for every step.
01
Font comparison
Compare the same sample across safe system-font stacks without requesting remote fonts.
Open tool02
Type scale
Generate heading sizes from a base size and ratio, and preview a page hierarchy.
Open tool04
CSS recipe
Export scoped typography CSS and a validated JSON recipe for reuse.
Open tool