Show HN: Justif – Knuth-Plass justification and microtypography for the web

Show HN: Justif – Knuth-Plass justification and microtypography for the web(justif.lyall.co)

72 points by lyall 4 days ago | 11 comments

Justif is a drop-in JavaScript library that progressively enhances web pages to TeX-level text justification. Installation is a single <script> line, standard text and accessibility affordances are unchanged, and users with JS disabled get native browser rendering.

I made justif because I've long been a fan of justified text. I think it looks clean and elegant, and makes reading more enjoyable. But bad justification is the opposite, with gaping spaces that distract me to the point of making the text near unreadable.

Browsers have got better recently at handling justified text [0][1], but still use suboptimal greedy algorithms for the most part, and are not near that TeX/InDesign level of quality that I crave. `text-wrap: pretty` exists but is far from a panacea, as you can see for yourself in the demo.

Justif also has the benefit of providing more consistent text layout across browsers. Blink (Chrome), Gecko (Firefox) and WebKit (Safari) all justify text differently, so normally what the user sees depends on what browser they use.

Take a look at the demo, play around with it, see if you can break anything. I'm open to improvements of the API design as well, so please let me know your thoughts.

For more details, see the README: https://github.com/lyallcooper/justif

0: https://cloudfour.com/thinks/justified-text-better-than-expe...

1: https://owickstrom.github.io/the-proportional-web/

torgoguys 1 hour ago |

I haven't looked at the API yet, but the demo is great on my phone. Instead of just justified blocks, can you have it do a "justified" (even amount of spacing) from an irregularly shaped right edge (in my case, an image on the right side of a design template I made)?

svat 4 days ago |

This is great! Loved the demo and controls (and nice touch to include The Frog Prince as one of the sample texts lol). I think by doing tracking and expansion you're going even further than original Knuth TeX did/does. Maybe for the demo when hyphenation is turned off, the browser side should also turn it off? Or leave it like this, justif without hyphenation still does better than browser with hyphenation :)

Wish this project great success!

lyall 4 days ago | |

Thank you! And yes by default TeX doesn't do tracking or expansion, but the microtype [0] package does.

And I did struggle a bit with deciding how best to do the comparison to native browser rendering. I wanted it to be an apples-to-apples comparison, but also didn't want to unfairly handicap the browser by disabling something like hyphenation. It's already bad enough as is...

0: https://ctan.org/pkg/microtype

svat 2 hours ago |

For OP: I think "Type specimen" should be the default sample text, just to get readers into the right spirit. :)

For anyone else reading this: make sure you click on the "controls & metrics" at the bottom to try out all the options (such as comparing with your browser's "text-wrap: pretty"); it's really cool!

lyall 1 hour ago | |

It is the default if you open the demo on a narrow screen! It has a more striking difference between browser and justif layouts at narrow widths than the Alice sample. But maybe you’re right and it should be the default for everyone.

antics9 3 hours ago |

Side-by-side didn’t do it for me but flicker made all the difference!

This is great, wish that browsers would implement a better algorithm.

Also good execution with the demo page.

airstrike 2 hours ago |

This demo feels about as good as eating a spoonful of tiramisu

vhwalke 2 hours ago |

Wow! I've spent the past few weeks setting 18th-century newspaper text on the web - justified, up to three narrow columns, period ligature, and the gap between CSS justification and real typesetting was a big part of the whole project. The browser's greedy line breaker plus hyphens: auto gets you maybe 80% there, and the last 20% is rivers, loose lines, and archaic words the hyphenation dictionaries have never met. "Fœderal" produces some genuinely creative break points. The result I got to I feel like is good, but not great.

Questions, from someone who wants this to work:

* Does Justif do its own hyphenation (Liang patterns?) or lean on the browser's? And is there a way to feed it exceptions for unusual or archaic spellings?

* How does it behave at narrow measures, say 35–40ch columns? That's where Knuth-Plass should shine most, but it's also where badness compounds fastest.

* What's the reflow cost on long documents (5–10k words) when the container resizes or the user scales the text — full re-run or incremental?

* Any thoughts on coexisting with text-wrap: pretty as browsers slowly grow real paragraph-level breaking?

Congrats on shipping this. I miss producing documents with TeX!

lyall 1 hour ago | |

Hyphenation: yes, justif does its own hyphenation. It ships with TeX’s hyphenation dictionaries for a bunch of languages, but supports custom dictionaries as well! See https://github.com/lyallcooper/justif#hyphenation

Narrow columns: open up the controls on the demo and try adjusting the width slider :)

Long documents: try the “Alice in Wonderland (long)” sample text in the demo to get a feel for how it handles long documents. In general it performs well enough I think, though Safari is a little slower than other platforms. It doesn’t do it incrementally (not sure that’s possible), but I spent quite a while trying to make sure it was fast enough to re-layout in real time even on long documents.

I haven’t thought about coexisting. I’m not sure how that could work but I’m open to ideas.

wrs 3 hours ago |

Chromium supposedly implemented Knuth-Plass for CSS's "text-wrap: balance", but reading the end of the tracking bug [0] it seems it stops at six lines? (Design doc: [1])

[0] https://issues.chromium.org/issues/40270471 [1] https://docs.google.com/document/d/1jJFD8nAUuiUX6ArFZQqQo8yT...

vhwalke 1 hour ago |

Follow-up, since I asked the questions above: I spent the evening running Justif against the hardest page I have: three 356px columns of 18th-century text set in IM Fell at ~17.6px with 24.3px leading. I came in curious and left planning the integration.

The numbers were better than I hoped. A full ~5k-word essay justified in about 280ms, and ~36KB gzipped including the en-US patterns. And the output is the part that sold me. The columns look like typesetting rather than CSS, which is the whole thing I'd been grumbling about.

The only snag I hit: a floated initial letter (drop cap) trips it — the first line ignores the float and overflows the gutter. Excluding that paragraph and leaving it on native justify renders perfectly, so it's cosmetic to work around, but a first-class exclusion selector would be lovely. I'll file an issue with the details and our measurements.

Best part: this experiment exposed that our sheets are currently set ragged right, which no printer in 1787 would have tolerated. Your library may be what finally makes us historically honest. Test page for context: federalistreader.org/papers/10/

Thank you for building this!