Save in Glyphs. See it in your proof.

Hellbox connects directly to Glyphs. Move a point, adjust your spacing, toggle a feature. It shows up in your proof before you can put your coffee down. Save your Glyphs file and your proof is already looking back at you.

Back and forth.

Hold Cmd and the glyph under your cursor lights up. Click it and it opens in Glyphs, ready to edit. Select a whole string and hit Return to send that over instead. Fix the outline, save, and the proof has already caught up by the time you switch back.

What you see is what you print.

You're working on the actual PDF the entire time, the same file the export writes. What comes off your printer is what was on your screen. Print whenever, bud.

A proof for every kind of staring.

Waterfalls, glyph sets, columns and rows, compare styles, simple text, and markup annotation. Each one built for a different kind of looking. Because you don't evaluate kerning the same way you evaluate texture.

Bring your own text.

Link a .txt, .rtf, or .md file to any section or grid cell. Edit the file, the proof updates. You can finally stop pasting the same kerning string into every document you open.

Proof with what you've drawn.

Click the wand and Hellbox writes proof text from your font's drawn glyphs. Twelve letters in, you proof twelve letters' worth of words. Save in Glyphs and the text grows with your font's repertoire.

Mix fonts in the same paragraph.

Auto mode distributes fonts across your text by weighted probability. Great for testing how a family reads in running copy. Manual mode lets you tag exact ranges with specific styles. Either way, you'll know fast whether your roman and italic are getting along.

Columns and rows. Then merge them.

Chop the page into a grid, then combine cells until it reads like a specimen spread. Every cell can run its own font, size, and text, or inherit from the section and behave. Complex layouts without a detour through InDesign.

Save the proof. Swap the font.

Pangrams, spacing tests, kerning pairs, diacritics for 26 languages. All built in as section templates. Proof templates save everything else: sections, fonts, settings, page size. Build your proof once, drop any font into it later.

If you give a shit about trees.

Freeze a PDF snapshot and mark it up right there. Freehand pen, text annotations, adjustable colors and stroke widths. Your notes live inside the proof file, not on a Post-it stuck to your monitor.

Proofs on every push.

Hellbox runs headless too. Commit a .fontproof next to your fonts and CI renders a fresh PDF on every push, failing the build if glyphs go missing or text overflows. Exports don't need a license on the runner. And when you just want a quick proof from a font file, the CLI renders one straight from the terminal.

Read the CI guide or fork the example repo.