hYYa ink — the hYYa ink mascot writing with a quill

hYYa ink Stop reading syntax. Start reading/editing documents.

The native viewer and editor that turns 16 formats — Markdown, JSON, CSV, Mermaid, LaTeX, Jupyter and more — into clean, readable documents you can edit, instantly, offline, and private.

Free to try. One in-app hYYa ink Pro unlock covers iPhone, iPad and Mac — buy it once, on any of them.

Your everyday files, the way they should look.

hYYa ink opens the files developers and writers deal with every day — Markdown, JSON, YAML, TOML, XML, CSV, Mermaid, LaTeX, Jupyter and more — and renders them the way they're meant to look, instead of as walls of raw text. No IDE to boot up, no cloud, no account. Just tap a file and read it. Built natively for Mac (Apple Silicon + Intel), iPhone and iPad, it opens in milliseconds, and nothing leaves your device unless you run an optional AI action with your own key.

Many formats, one calm reading view.

Turn a scan into a document

A scanned page is a picture of words rather than words, so searching it finds nothing, you cannot select a line, and the AI actions have nothing to read. Make Searchable reads the page and puts the text back — the scan becomes searchable, selectable, and something the AI actions can actually work on.

Recognition runs on your device — nothing is uploaded. It covers around thirty languages and picks them out automatically.

Find your way around it

Find in document highlights every match and keeps a live count as you type. Pages and contents puts page thumbnails beside the document’s own outline. And a password-protected PDF simply opens — hYYa ink asks you for the password.

All three are free — no trial, no account.

Mark up PDFs by hand iPhone, iPad & Mac

On iPhone and iPad, mark up any PDF by hand — with Apple Pencil or a finger, using the system tool set. A single session can span several pages. Your ink stays adjustable while the document is open; saving writes a new PDF and leaves your original untouched.

On the Mac, draw with your trackpad or mouse using pen, marker, pencil and eraser, in five ink colours with adjustable thickness, and undo stroke by stroke. One session spans several pages and saves once — and, exactly as on iPad, your ink stays adjustable until you do. Only in the saved copy does it become part of the page.

PDF: add text, sign & export

Open any PDF and add text anywhere — tap the exact spot you want and type. hYYa ink never hunts for fields or boxes. Sign by hand in black or blue ink, then resize, rotate and reposition it. Undo any step, and save a copy that leaves your original untouched — all on device.

Organise, protect, compress, compare

Organise Pages reorders, rotates and removes pages, and pulls pages in from another PDF. Protect sets a password and decides whether printing and copying are allowed. Compress shows the before-and-after size before you commit to it. Watermark previews live as you set the wording. Compare shows which pages differ between two versions. And Mark Up Text highlights, underlines or strikes through the text you select.

Every one of these writes a new file. The PDF you opened is never modified.

Markdown, rendered

Headings, bold/italic, links, lists, code blocks and quotes, in a clean reading layout.

Structured data trees

JSON, YAML, TOML and XML as collapsible, color-coded trees — structure at a glance.

CSV & TSV grids

Spreadsheets as tidy tables, with the header row highlighted.

Live diagrams

Mermaid and Graphviz (DOT) render instantly, fully offline.

Math, typeset

LaTeX math, typeset cleanly with KaTeX.

Jupyter notebooks

.ipynb notebooks as clean, readable documents.

AsciiDoc & Org-mode

Long-form docs in a clean reading layout.

Diff & log files

diff, patch and log files, syntax-highlighted.

AI assistance, opt-in

One tap to Explain, Summarize, Reformat, Fix errors or Make diagram — bring your own key, off by default.

Quick Look built in

Press Spacebar in Finder to preview any supported file, beautifully.

Opens by double-click

Registers your file types so they just open.

Native, fast, private

SwiftUI, opens in milliseconds, zero tracking, zero data collection — works with no internet.

Universal & modern

One app for Mac (Apple Silicon and Intel, macOS 14+), iPhone and iPad (iOS/iPadOS 17+).

One engine, every screen you own.

Screens from the Mac, iPad and iPhone apps — the editor, then the PDF tools on every one.

Split view in hYYa ink on macOS — Markdown source on the left and the rendered document on the right, with Edit, Split and Preview in the toolbar
On Mac — edit and preview side by side
The formats guide in hYYa ink on macOS — sixteen tiles listing Markdown, AsciiDoc, Org, JSON, YAML, TOML, XML, CSV, TSV, Mermaid, Graphviz, LaTeX, Jupyter, Diff, Log and PDF
Sixteen formats render natively — anything else opens as source

Read a scan, find any word, browse by page — on every platform

Make Searchable in hYYa ink on macOS — text recognised on a scanned invoice and selected on the page, with the Tools menu open, naming organise pages, make searchable, protect, compress, watermark and compare
Make Searchable — on-device text recognition
Find in document in hYYa ink on macOS — every occurrence of a word highlighted at once across the page
Find in document — every match, live count
Pages and contents in hYYa ink on macOS — page thumbnails in a sidebar beside the page, with the current page highlighted; the PDF’s own contents appear in the same sidebar when it carries them
Pages and contents — thumbnails beside the page

The PDF tools — Add Text, Markup and Sign, on every platform

Adding text anywhere on a PDF in hYYa ink on macOS — typed entries placed straight onto a certificate form, with Add Text selected in the toolbar beside Markup and Sign
Mac — tap anywhere and type
Marking up a PDF by hand in hYYa ink on macOS using a trackpad — a highlighted line, a circled figure and handwritten margin notes, above the pen, marker, pencil and eraser tools with five ink colours
Mac — markup with a trackpad or mouse
Signing a PDF in hYYa ink on macOS — a handwritten blue-ink signature drawn with a trackpad and placed on an equipment loan agreement, with Sign selected in the toolbar beside Add Text and Markup
Mac — sign with a trackpad
Adding text to a PDF in hYYa ink on iPadOS — tapping straight onto a certificate form to type, with no form fields to hunt for
iPad — no fields to hunt for
Marking up a PDF by hand with Apple Pencil in hYYa ink on iPadOS — a highlighted budget line, a circled figure and handwritten notes, with the ink colour palette below
iPad — markup with Apple Pencil
Signing a PDF in hYYa ink on iPadOS — a handwritten blue-ink signature drawn with Apple Pencil and dragged into place on an equipment loan agreement
iPad — sign with Apple Pencil
Adding text to a PDF in hYYa ink on iOS — tapping anywhere on a certificate form to type, leaving the original page untouched
iPhone — the original stays untouched
Marking up a PDF by hand with a finger in hYYa ink on iOS — handwritten notes and a highlighted line on a page of meeting notes, with the ink colour palette below
iPhone — markup with just a finger
Signing a PDF in hYYa ink on iOS — a handwritten blue-ink signature drawn with a finger and dragged into place on an equipment loan agreement
iPhone — sign with a finger

One light app that respects your files.

Other tools make you choose: a heavy IDE, a single-format viewer, or a cloud note app that imports your files into its world. hYYa ink is one lightweight, local-first app that renders many formats natively — and respects that the files are yours.

Read, export and print — all free, forever.

No account, and no trial to expire. Finding a word, browsing by thumbnail and opening a password-protected PDF are free too. Editing and the PDF tools come as a 7-day free trial you start when you choose — how long it runs, what stops working after it, and the one-time price are all shown before it begins. Then a one-time Pro unlock: a single purchase, never a subscription. One Universal Purchase covers iPhone, iPad and Mac.

hYYa ink: what is free forever and what the 7-day trial and one-time Pro unlock add
Feature Free Forever · no account Pro 7-day free trial, then pay once
Reading & output
Open and read every supported formatMarkdown, JSON, YAML, TOML, XML, CSV/TSV, Mermaid, Graphviz, LaTeX, Jupyter, diff, log, AsciiDoc, Org and PDF
Preview mode
Export to PDF
Print
Find in documentevery match highlighted, with a live count
Pages and contentsthumbnails beside the document’s own outline
Open password-protected PDFs
Editing
Edit in source and split modesFree stays in Preview
Edit JSON, YAML and XML treesFree is read-only
Edit CSV and TSV gridsFree is read-only
Markdown formatting toolbar
PDF tools
Add Text
Markup by handApple Pencil or finger on iPad and iPhone, mouse or trackpad on Mac
Sign
Save a filled copy
Mark Up Texthighlight, underline or strike through selected text
Make Searchableon-device text recognition, so a scan can be searched
Organise Pagesreorder, rotate, remove, or insert pages from another PDF
Protecta password, plus printing and copying permissions
Compressthe before-and-after size, shown before you save
Watermark
Comparewhich pages differ between two versions
AI
AI actionsBring your own key — hYYa runs no AI server
Reading & output
Open and read every supported formatMarkdown, JSON, YAML, TOML, XML, CSV/TSV, Mermaid, Graphviz, LaTeX, Jupyter, diff, log, AsciiDoc, Org and PDF
✓ Free✓ Pro
Preview mode
✓ Free✓ Pro
Export to PDF
✓ Free✓ Pro
Print
✓ Free✓ Pro
Find in documentevery match highlighted, with a live count
✓ Free✓ Pro
Pages and contentsthumbnails beside the document’s own outline
✓ Free✓ Pro
Open password-protected PDFs
✓ Free✓ Pro
Editing
Edit in source and split modesFree stays in Preview
— Free✓ Pro
Edit JSON, YAML and XML treesFree is read-only
— Free✓ Pro
Edit CSV and TSV gridsFree is read-only
— Free✓ Pro
Markdown formatting toolbar
— Free✓ Pro
PDF tools
Add Text
— Free✓ Pro
Markup by handApple Pencil or finger on iPad and iPhone, mouse or trackpad on Mac
— Free✓ Pro
Sign
— Free✓ Pro
Save a filled copy
— Free✓ Pro
Mark Up Texthighlight, underline or strike through selected text
— Free✓ Pro
Make Searchableon-device text recognition, so a scan can be searched
— Free✓ Pro
Organise Pagesreorder, rotate, remove, or insert pages from another PDF
— Free✓ Pro
Protecta password, plus printing and copying permissions
— Free✓ Pro
Compressthe before-and-after size, shown before you save
— Free✓ Pro
Watermark
— Free✓ Pro
Comparewhich pages differ between two versions
— Free✓ Pro
AI
AI actionsBring your own key — hYYa runs no AI server
— Free✓ Pro

Pro is a single in-app purchase — buy it once on iPhone, iPad or Mac and it unlocks on all three.

Stop reading syntax.
Start reading/editing documents.

Free to try. Local-first. Opens in milliseconds — on Mac, iPhone and iPad.

Get it on the App Store

Free to try · iPhone, iPad & Mac on the App Store · macOS 14+ (Apple Silicon & Intel), iOS/iPadOS 17+

Frequently Asked Questions

What is hYYa ink?

hYYa ink is a native app for Mac, iPhone and iPad that opens the files developers and writers deal with every day — from Markdown and JSON to CSV, Mermaid, LaTeX and Jupyter — and renders them the way they're meant to look, instead of as walls of raw text. No IDE to boot up, no cloud, no account: just tap a file and read it.

Which file formats does it support?

hYYa ink renders 16 formats. Markdown (.md) in a clean reading layout with headings, bold and italic, links, lists, code and quotes; JSON, YAML, TOML and XML as collapsible, color-coded trees; CSV and TSV as tidy grids with a highlighted header row; Mermaid and Graphviz (DOT) diagrams rendered live and fully offline; LaTeX math typeset with KaTeX; Jupyter (.ipynb) notebooks; AsciiDoc and Org-mode documents; diff/patch and log files, syntax-highlighted; and PDF, rendered page by page.

Is it free?

Opening and reading every supported format is free forever, and so are Preview mode, exporting to PDF, printing, Find in document, Pages and contents and opening password-protected PDFs — no account, no trial needed. A 7-day free trial you start when you choose then unlocks editing (source and split modes), the PDF tools — Add Text, markup by hand, Sign, Save a filled copy, Mark Up Text, Make Searchable, Organise Pages, Protect, Compress, Watermark and Compare — editing JSON, YAML and XML trees and CSV/TSV grids, the Markdown formatting toolbar, and AI actions with your own key. After the trial those need a one-time Pro unlock, a single purchase and never a subscription; one Universal Purchase covers iPhone, iPad and Mac.

Does it work offline?

Yes. All viewing and editing works with no internet connection at all — including live Mermaid and Graphviz diagram rendering and LaTeX math. By default, nothing leaves your device. The only exception is the optional AI assistant, which sends the open document’s text to the provider you connect with your own key, and only when you run an AI action.

Is my data private?

hYYa ink is local-first with no accounts, no tracking, and zero telemetry. By default, nothing leaves your device. The only exception is the optional, off-by-default AI assistant: when you use it, it sends the open document’s text to the OpenAI-compatible provider you connect with your own key — or, on the Mac, to a local model you run yourself — and only when you run an AI action; the app has no AI server of its own.

Which devices does it run on?

hYYa ink runs on Mac — both Apple Silicon and Intel, on macOS 14 Sonoma and later — and on iPhone and iPad running iOS/iPadOS 17 and later. Pro is one Universal Purchase across your iPhone, iPad and Mac — buy it once on any of them and it unlocks on all three.

Does it work with Quick Look?

Yes. hYYa ink includes a Quick Look extension — press the Spacebar on any supported file in Finder to preview it, beautifully rendered, without opening the app.

Can I edit files?

Yes. Viewing is free forever; editing is a 7-day free trial, then included in the optional one-time Pro unlock — a single purchase, not a subscription.

Can I mark up a PDF by hand?

Yes — on iPhone, iPad and Mac. On iPad you mark up with Apple Pencil or a finger using the system tool set; on iPhone with a finger; on the Mac you draw with your trackpad or mouse, with pen, marker, pencil and eraser. Either way you get five ink colours, adjustable thickness and undo stroke by stroke, and a single session can span several pages. Your ink stays adjustable for as long as the document is open — nothing is written until you save, and saving writes a new PDF that leaves your original untouched. In that saved copy the ink is part of the page, so it survives export, print and other PDF viewers.