RyDF is a macOS PDF viewer, markup and print app built for large, complex drawings. It stays fluid on files that bog other viewers down — with a full annotation toolset, to-scale measuring, OCR for scans, and a real print pipeline.
RyDF is one focused app that reads big PDFs smoothly, lets you mark them up like a pro reviewer, measures right off the drawing, and prints exactly what you need.
A tiled, virtualized engine keeps huge multi-hundred-page and CAD-size PDFs fluid — smooth scroll, instant zoom, and pages kept warm in RAM.
Clouds, shapes, text, callouts, dimensions, ink, highlighter, stamps and signatures — a complete Design-Review-style annotation set.
Calibrate a page's scale once, then read true distances and areas straight off the drawing — with snap-to-geometry for exact points.
A real print pipeline — pick paper size, scale to fit, print selected pages, and get a faithful preview before anything hits paper.
Drop in a drawing, review it with the full toolset, and save — your markups go straight into the PDF file, so there's nothing extra to keep track of. Or take it further with measuring, OCR and printing.
The classic markup loop — comment, cloud, and hand it back.
Turn a scaled drawing into real numbers, then print what you need.
Built for people who live in technical PDFs all day — fast where it counts, thorough where it matters, and quiet the rest of the time.
A priority-scheduled, tiled render engine with a RAM page cache — big CAD sets and hundred-page documents stay smooth to scroll and zoom.
Rectangles, ellipses, revision clouds, lines, arrows, polylines, ink, highlighter, text boxes, callouts and notes — with color, fill, stroke and opacity.
Drop reusable stamps with repositionable text, and sign by typing your name in a cursive font or importing an image with the background removed.
Per-page scale calibration (draw a known length, type its real value), snap-to-geometry for exact endpoints, and a quick-measure tape that leaves nothing behind.
Recognize text on scanned or image-only pages with on-device Apple Vision — an invisible, searchable text layer is baked in, so scans become selectable and searchable.
Save writes your markups into the PDF file itself — no stray sidecar, one file to keep or send, and still fully editable when you reopen it in RyDF.
Rotate, delete, extract, insert and reorder pages — inline in the sidebar or in a full grid view, drag-and-drop like Acrobat's Organize Pages.
Full paper-size table, scale-to-fit, print the whole document or just the pages you selected, and a true-to-output preview before you commit.
Keep several drawings open at once and flip between them instantly — each tab holds its own place, zoom and markups.
Search the whole document with paged results and adjustable on-page highlights — and it finds text you added with OCR, too.
Work in mm, inches or points; type fractions and arithmetic into any dimension field (1/8", .25"−1/8"); light or dark, following your system.
Checks its GitHub releases for new versions, shows what changed, and downloads the update — on a schedule you choose or only when you ask.
Calibrate a page once — draw across something you know the length of, type the real value, and optionally snap to the drawing's own line endpoints for a pixel-exact reference. From then on every measurement on that page reads out in your units. Scale is remembered per page, so a set with different sheet scales just works.
The blue line is snapped to two wall corners; you type the known length and RyDF sets the page scale.
It's free while it's in alpha, and under active development. Grab the latest build, open your gnarliest PDF, and send the bugs and requests our way — feedback shapes what comes next.