From Idiotproofed to
Font Proof Hellbox

It was 2018 and I was drawing a couple of typefaces, Goiters and Boxout. My friend Kyle Wayne Benson of Very Cool Studio was drawing Gooper. Here is how you checked your work back then.

You export the font. You open a layout app. You relink the files. You fix the styles. You print. You squint. You find the lowercase g you botched three days ago. You close everything, go back to the outlines, fix it, and then you do the whole dance again. Every font. Every revision. Forever.

Font proofing is quality control for people who love letters. A font proof is where you catch the mistakes before a stranger hands you their money. It was tedious and detached from the type design process.

So in October 2018, Kyle and I built ourselves a shortcut and called it Idiotproofed. Drag a font into the browser and it proofs it, live. Hamburgefontsiv at display sizes. Spacing tests. Pangrams, kerning strings, italics, diacritics, Greek, Cyrillic. Sliders for size, leading, and weight. Checkboxes for OpenType features. A button that prints the whole thing to PDF.

The description on the GitHub repo has always read “A font proof for idiots.” We were the idiots.

Idiotproofed at idiotproofed.com, proofing Kyle’s Gooper at version 0.002, last edited October 14, 2018.

The idea was one idea: the proof keeps up with you. Drop in a new build and every page re-renders. Nudge a slider and the whole document flinches. The whole dance from before, the exporting and the relinking and the printing, collapses into save and look.

Run it locally and it did the real trick. Idiotproofed watched your fonts folder: export a new build and every open proof reloaded, by itself, every save. Live reloading as you work, in 2018! Nothing else proofed fonts like that. The reason we built it, as the README still states, was: “so we’d never have to open InDesign again.”

Font testers in the browser existed before ours. Pablo Impallari’s Font Testing Page was the workhorse of the era. It went down for several months, and we missed it badly enough to build a replacement. Idiotproofed added the real-time part.

And the browser giveth, and the browser taketh away. A browser proof shows you how your font behaves in a browser. The PDF button worked by screenshotting the page, so what you printed was an image of your font. Zoom in and the curves you drew turn to pixels.

The right idea in the wrong place, and it refuses to stay in the past tense. It is still up at idiotproofed.com, it still does the job, and a patch that landed this week taught it to watch the font files you pick without the need to run the app locally. So in Chrome a re-export reloads the proof on its own. Drop a font in and see.

The native version

In 2024 I started over, native, on the Mac. With help from Georg Seifert, who makes Glyphs, the app was talking to Glyphs through the Glyphs SDK very quickly. About 1,200 commits later, here we are.

Here is what “here” means. Hellbox renders with the same text engine as every real Mac app, so what you proof is what your users get. What you proof is what you print. The pages it makes are real paginated PDFs, the kind you can hand to a printer or a client. RoboFont and FontLab support are in beta. And the folder trick from 2018 grew up: Hellbox watches the Glyphs file itself, so even the export step disappears. Save, and the open proof updates. Though the Hellbox brand has a lot of personality, I wanted the app itself to fade into the background and align closely with native applications. So I followed the HIG for the most part and drew inspiration from other UI, like the Figma properties panel.

Hellbox in 2026, proofing the same typeface. Gooper made it to release. So did the app.

Put the two screenshots side by side to see their overlap and progression. Hellbox is Idiotproofed, grown up.

Same proof, same typeface.

About the names

Idiotproofed was about making it stupid simple to proof a font while designing. Catching dumb mistakes early.

Hellbox is about extending that original concept from 2018 and making it even better. In an old print shop, the hellbox is where the broken type goes. The worn letters, the cracked letters, tossed in a bin, hauled to the furnace, melted down, cast into new type. Everything in the hellbox gets to be type again. The apprentice who hauled it was called the printer’s devil, and that is the little demon you will meet on the homepage. A tool whose whole job is finding the broken parts of your typeface, named after the box of broken type. It took most of a decade to arrive at the obvious.

In 2018, Gooper was a baby, Goiters and Boxout were in the womb, and the tool was a tab in a browser. All three fonts shipped. The tool grew teeth. And the idea is still the one idea: the proof keeps up with you.

Hellbox is out now for macOS, with a 14-day free trial. And if you were one of the handful of people who used Idiotproofed since 2018, thanks for waiting. This is what it wanted to be.

An acknowledgment

Hellbox started as Font Proof. Idiotproofed has always been “A font proof for idiots” after all, and fontproof.com had been redirecting to idiotproofed.com for eight years. So when it came time to roll out what I had been working on, it made sense to use that domain. Some folks pointed out potential confusion with the similarities between fontproof.com and fontproofer.com, another great tool used by many, created by Peter Nowell. Rather than ask a small community to keep two similar names straight, I gave the app its own name. Hellbox it is.