Features

Markups

Draw your own, or work with the markups already in a file.

• Drawing tools19, from clouds to links
• From other PDF appsOpen as markups you can edit
• Markups listYour columns, filters and CSV
• PropertiesLine, fill, hatch, opacity and font
• Text markupsHighlight, underline and strikeout
• Match propertiesOne markup's look on others
• SnappingTo drawing lines and markups
• Arrays and groupsRows, columns, groups, rotation
• SnapshotsCopy lines and recolour them
• SpellingChecked as you type
• Saved in the PDFStandard PDF annotations

Speed

Fluah's release tests on 28 October 2026, medians of five launches, on a 16‑core desktop PC with a 300 Hz display.

0.57 sFirst page sharp

1. 0 sDouble-click
2. 0.29 sWindow open
3. 0.41 sInterface loaded

0.57 s

From launch to the first page, sharp, of 44 A1 CAD sheets, 51.6 MB.

0.61 s

From launch to the first page, sharp, of six A0 sheets carrying 926 site photos, 284 MB.

17 to 28 ms

From one page of the standard to the next, sharp.

3.3 ms

Between frames while a sheet pans: every refresh of a 300 Hz display.

Its own engine

Fluah draws pages with its own PDF engine.

Every core

Drawing is spread over the cores Windows lets Fluah use.

File Explorer

A file's pages, layouts or picture in the preview pane, without opening an app.

• .pdf
• .dwg
• .png
• .jpg
• .jpeg
• .jpe
• .jfif
• .heic
• .heif
• .hif
• .md
• .markdown

• PagesButtons and a typed page number
• Zoom and panWheel zoom, middle-button pan
• TextSelect and copy, labels included
• LinksGo to the page they name
• Pictures24 MP HEIC in 81 to 143 ms
• ThumbnailsFirst page as the file's icon

Estimate

Take off quantities and price them, in a mode of its own.

• FindOne boxed symbol counts them all
• StagesGrouped, shown or hidden
• Price listsYour prices, your markup
• Export.xlsx or .csv
• JobsSaved with their sheets

Compare

Two issues of a set, and the changes between them.

• Previous and currentDrop the old issue, swap in one click
• Changes on the sheetNumbered and listed by page
• Revision cloudsLeft out, on by default

Collaborate

One PDF, marked up by several people at once.

• ProjectsAdmin, Editor or View only
• Any PDFYour file stays where it is
• LiveMarkups, pointers and selections
• Hide someoneTheir pointer, never their markups
• Undo and offlineYour own edits, synced when back
• SealedAES-256-GCM before it leaves your PC
• Storage100 MB a project, 2 GB a company
• Turn it onSettings > Workspace > Modes

Signatures

Sign with your digital ID, one page or every page.

• Digital IDsA .pfx file, Windows' store or a new one
• Your signatureName, picture and logo, sealed
• UnlockLocks again after 30 minutes idle
• Sign in placeA 51 MB set in under a second
• Batch signOne place on every page
• CheckedChanges since signing shown
• Checked laterRevocation data for IDs from a certificate authority
• The formatPKCS #7, SHA-256, full chain

File tools

Tools that change the file itself.

• Reduce file size54 MB of drawings to 27 MB
• Searchable scansOCR text to search and copy
• FlattenMarkups drawn into a copy
• Save and auto saveInto the file you opened
• RecoveryUnsaved markups offered back