Private by architecture — nothing uploaded

The PDF studio that never uploads your files.

Acrobat-grade power. Notion-grade calm. Organize, convert, edit, optimize and secure every PDF — entirely on your own machine.

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FoliaFolia research-paper.pdf
On-Device Document Processing for Privacy-Preserving PDF Workflows
J. Park · M. Olsen · K. Reza
Correspondence: [email protected]
Abstract
We present a document-processing pipeline that performs conversion, editing, optimization and redaction entirely on the user's machine. No page content, metadata, or derived artifact is transmitted to a remote service. Each operation re-reads its own output to verify integrity before the result is shown to the user.
1. Introduction
Portable Document Format remains the default container for legal, academic and financial records. Yet most tooling routes files through cloud infrastructure, expanding the trust boundary far beyond the author's intent.
Our approach keeps every byte in process memory. We show that local execution matches server-side throughput for documents up to one hundred megabytes while eliminating network exposure entirely.
Verified result
Redaction
Re-extracted text — 0 remain.
Encryption
Reopened — AES-256 (V5/R6).
PDF → Word
Layout-faithful — fonts kept.
0 network calls
Nothing leaves your device
Processed in-memory, on-device
Built for ResearchersLegal & financeMedical & govStudentsMultilingual prosGeneral useHeavy useSensitive documents
Why Folia

Three unhappy options. One calm answer.

Everything people reach for today asks them to give something up — money, privacy, or capability.

vs Adobe Acrobat
Heavy, expensive, subscription-locked and cluttered.
Calm and focused, with a generous free tier and a one-time Lifetime option.
vs free online tools
They upload your file to a stranger’s server.
100% of the work runs on your machine — the file never leaves the device.
vs built-in viewers
View-only. They can’t actually change anything.
Edits, converts, redacts, signs, OCRs and more — for real.
The five pillars

What we build everything around.

Private by design
Nothing is uploaded. Enforced by the app’s architecture, not just a promise.
Genuinely complete
24 headline tools plus Document Tools, Power Tools and an AI platform.
Honest & verified
Operations re-read their own output to prove they actually worked.
Truly multilingual
Fully EN + KO interface; the text editor handles 40+ scripts.
Calm & fast
Pixel-crafted, token-driven, keyboard-first, light & dark.
Genuinely complete

Everything you do to a PDF, in five categories.

24 headline tools that replace a stack of separate apps and sketchy upload sites.

Organize
Arrange, split & combine pages
Merge PDFs
Split
Extract pages
Delete pages
Insert from file
Reorder
Rotate
Duplicate page
Convert
Move between PDF & other formats
PDF → Word
PDF → Excel
PDF → PowerPoint
PDF → Image
Images → PDF
Office → PDF
Edit
Change content & add markups
Edit existing text
Add text FREE
Whiteout
Rich text
Highlight FREE
Underline / Strike
Pen / Draw
Text notes FREE
Redact
Watermark
Page numbers
Forms
Sign
Optimize
Shrink & read your documents
Compress
OCR — 90+ languages
Security
Protect, sign & lock down files
Protect — AES-256
Digital signature (PAdES)
Unlock
Flatten
Sanitize
Bates numbering
Search & redact
Plus Document Tools, Power Tools & AI
Sanitize, Bates, PDF/A, Compare, Measure, Batch and the on-device AI platform.
See the full catalog
Privacy & verification

Nothing uploaded. And it proves its work.

Folia is a hardened desktop app — document bytes are processed in-memory, on-device. A fresh install makes essentially zero network calls until you opt in. Destructive and security operations re-read their own output to prove they actually worked.

Local-first by architecture — a sandboxed renderer with no hidden network calls.
Network-off-by-default — a fresh install is fully offline until you opt in.
Clearly-flagged exceptions — only consented plugins and one-time downloads ever reach out.
Real cryptography — verified AES-256 and PAdES handled in an isolated process.
Redaction
re-extracted text · 0 remain
PASS
Encryption
reopened · AES-256 (V5/R6, 256-bit)
PASS
Sanitize
metadata re-counted · clean
PASS
Folia never fakes success — “Done” is always evidence.
Edit existing text
beforeTeh resluts were significant.
afterThe results were significant.
Same font, color and size — even in 40+ scripts:
English中文हिन्दीEspañolFrançaisالعربيةবাংলাPortuguêsРусский日本語한국어DeutschTiếng ViệtไทยעבריתΕλληνικάदेवनागरीខ្មែរLatin
Edit · Multilingual

Edit a finished PDF — in its own font, in any language.

Click any line of real text and retype it. Folia matches the document's own embedded font, samples the ink and background color, and width-fits the replacement so nothing shifts. The text editor handles Korean, Arabic, Hebrew, Thai, Devanagari, CJK and Khmer — with right-to-left and complex-script shaping that other tools turn into boxes.

40+
scripts shaped correctly
~70
curated open-source fonts
EN · KO
100% bilingual UI
AI platformBETA

AI that reads your documents without sending them anywhere.

Every AI feature runs through one gateway. Folia Local AI runs entirely on your device — private and free. The model downloads once and then works with no network at all, so the text of your document never leaves your machine. A per-document "Local only" lock is there as well, for files you want kept strictly on-device no matter what.

Chat with citationsSummaries & study guidesRewrite & proofreadRead-aloud
AI AssistantLocal engine
Summarize the methodology and cite pages.
The study used a randomized controlled design (n=240) over 12 weeks [p.4], with double-blind allocation [p.5].
Study guideKey termsMind-map
Convert with real fidelity

PDF to Word that still looks like your PDF.

Layout-faithful, not reflowed — same fonts, same colors, real tables, exact positions. Locally.

Source PDF
Editable .docx
PDF → WordPDF → ExcelPDF → PowerPointPDF → ImageImages → PDF
Sign · Fill · Send

Sign it yourself — or collect signatures and watch them land.

Fill any form and sign on-device with a drawn or uploaded signature, then apply a tamper-evident PAdES digital signature. Need others to sign? An optional send-for-signature service (coming soon) will let you follow every step — Sent → Opened → Signed — in real time, with documents end-to-end encrypted and removed the moment everyone has signed.

Drawn or uploaded signaturePAdES digital signatureFillable formsReal-time status
Signature request 2 signers
Service-agreement-v3.pdf
Sent today · 14:02
You signed
On-device · PAdES applied
Done
Opened by J. Park
Opened
Awaiting M. Olsen
Pending
End-to-end encrypted · removed after signing
Power tools

For the professionals who push hardest.

Compare documents
Word-level diff between two PDFs, page by page — additions in green, deletions struck in red, with whole-document totals.
Measure
Click for distance or area on the rendered page, and calibrate a real-world scale from a segment of known length.
Batch processing
Apply a chain of tools to many PDFs at once — resilient per file, with a review step and save-all into a folder.
By the numbers

What Folia actually does.

Your documents are processed on your own computer — every tool, every time.

0
files uploaded, ever
24
headline tools
90+
OCR languages
40+
scripts shaped
Pricing

Free to start. Buy once, keep forever.

A genuinely useful free tier, low subscription prices, and a one-time Lifetime license — no Acrobat-style subscription lock-in.

Free
View, annotate & note — forever, no account.
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Student
Organize + everything in Free, verified by school email.
$1.00/mo
billed annually
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Professional
Every tool, for heavy daily users.
$4.00/mo
billed annually · or $5.00 monthly
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Lifetime
Pay once, keep forever. Local AI unlimited.
$50once
Folia 1.x · free updates within v1.x
Buy Lifetime
Enterprise & teams
Volume licensing, offline machine-locked activation, deployment help and priority support — at a price that scales with your seat count.
Talk to us
Nothing uploadedWorks offlineVerified AES-256Your keys never touch the UI
More than a desktop app

Folia fits the way you already work.

It slots into your file manager, your Office files and even your phone — and your documents stay on your device throughout.

Right-click to open
A File Explorer and Finder entry opens any PDF straight into Folia — no upload dialog, no browser tab.
Your default PDF reader
Set Folia as the system viewer and every PDF you double-click opens in a calm, fast, private workspace.
Office & images in
Drop Word, PowerPoint and images onto Folia to rebuild them as a single clean PDF.
Scan from your phone
Pair over your own local network and captured pages arrive on the desktop — never routed through anyone’s cloud.
Command palette
Every tool is one keystroke away. Folia is keyboard-first, so power users barely touch the mouse.
Settings sync, not files
Your accent, shortcuts and preferences follow you between machines. Your documents never do.
Windows
Available now

NSIS installer. No file-size limit — work with documents of any size. No account needed for the free tier.

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macOS
Coming soon

A universal build for Apple Silicon & Intel is in active development — same tools, same privacy. Tell us where to send the launch news.

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FAQ

Questions, answered honestly.

From privacy to pricing — the answers to everything people ask, gathered in one place.

Browse the full FAQ

Your documents never leave your device.

Start free today — no card, no account, nothing uploaded.

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