Hardcopy — make, read & move with QR

Hardcopy QR tools

Make a QR code

Turn text or useful information into a QR code you can scan, save, share, or print. Create links, Wi-Fi access, contact cards, messages, locations, or plain text. Customize the design and watch the code update as you edit.

Content

Kind

0 characters

Secret

Any phone camera can open it

With a passphrase, the words are locked (AES-256) before they become the code. Anyone can scan it; only the passphrase opens it — here, or in any copy of Hardcopy. There is no reset: lose the passphrase and the words are gone.

The format, for anyone writing a reader

The code holds HCS1: and RFC 4648 base32 (no padding), on its own or after a link ending in #. Decoded, in order: version (1 byte, 1) · cost c (1 byte; PBKDF2 iterations = c × 100 000) · flags (1 byte; bit 0 deflate-raw, bit 1 hint) · if hinted, its length and the hint in UTF-8 · salt (16) · IV (12) · AES-256-GCM ciphertext with its 16-byte tag.

Key: PBKDF2-HMAC-SHA256 over the passphrase in Unicode NFC. Every byte before the salt is authenticated as additional data. What comes out is UTF-8 text — a link, a Wi-Fi network, a contact, anything a plain code could hold.

Look

Code

Colours

Background

Colours

Shapes

Corner frame

Corner centre

Give the corners their own colour

Corner colours

Centre mark

—

Size (% of code)

Clear space behind it

A mark in the middle covers real modules. Error correction pays for them, so the level jumps to H while a mark is in place — and the test scan below is the only opinion that counts.

Frame & caption

Quiet border (modules)

Corner rounding

Outline

The quiet border is the blank margin a scanner needs to find the code at all. Four modules is the standard; below two, expect trouble.

Reading

Error correction

Every redraw is rasterised and handed to this app’s own decoder — the same one the camera uses. If it reads there, it will read on paper.

Picture

Vector

Read QR codes

Scan codes from another screen, a label, or a printed page, or import photos and screenshots to read them in batches. Results collect in a local history, with duplicates highlighted instead of added again. Secret codes can be unlocked here with their passphrase.

Camera

Which camera

Beep when a new code lands

Start, stop, the light and the camera flip sit on the picture itself, so nothing here needs scrolling back to mid-scan. The camera stops by itself when you leave this tab or the page goes to the background.

From a pictureImport screenshots or photosEvery code in every picture is read

A picture can also be pasted straight in (Ctrl / ⌘ V) or dropped onto the history.

History

Keep it on this device

Kept in this browser only. Nothing is sent anywhere — which also means clearing the browser’s site data clears the history.

File → QR pages

Convert a file into numbered QR tiles arranged on printable pages. Print them, save them as a PDF, and scan the pages later to reconstruct the original file. Tiles identify themselves, so pages can be captured in any order; optional redundancy helps recover from damaged or missing pages.

Drop a file hereor tap to choose one

Author

Print it on encrypted pages too

Paper

Size

Custom (mm)

Orientation

Margin (mm)

Printer reserve, all four sides (mm)

Every printer keeps a strip of the paper for itself, and no browser will tell a page what that strip is. Safari and Chrome on iOS also print a web address and a page number of their own into it, so allow about 16 mm there; a desktop browser with margins switched off can take 0. Too low and the bottom row drops onto a blank page of its own while the last column runs off the right-hand edge. Too high and you lose a row or a column — if you want that column back, shrink the module size rather than the reserve.

Density

Compress before printing

Pick the densest code size for me

Module size (mm)

Printer resolution (dpi)

Code size (version)

Error correction

Gap between tiles (mm)

Each code already carries a blank border of its own, so a small gap is enough.

Print tile numbers

Numbers make it easy to find a particular tile by eye and to re-sort a dropped stack. Each tile also states its own position inside the code, so turning them off is safe and buys back a row.

Preview

Draw a few sheets at a time

Wait no longer than

A long document takes minutes to draw in full, and every setting you touch starts that over. Left on, only as many sheets as fit in the time above are drawn at once — so a change shows up straight away and the printer keeps moving while you decide. Turn it off and each batch runs as large as this device’s memory will bear.

Redundancy

Cover & privacy

Preview on first page

Waiting until you stop typing — encrypting and re-tiling the whole file takes a moment. Press Enter to apply it now.

Print file name when encrypted

Encryption is AES-256-GCM with a key derived from the passphrase (PBKDF2, 250k rounds). The name and type ride inside the ciphertext, so an unnamed stack of pages reveals nothing but its size.

What you get

Presets are named for how you plan to read the pages back, because that — not the printer — is what limits density. The calibration sheet prints the same tile at several module sizes. Scan it in QR pages → file to learn the smallest module your printer and scanner agree on, then set it above.

QR pages → file

Rebuild a file from its QR tiles. Use the camera, import photos or scans, or bring in a PDF. The reader finds tiles wherever they appear and accepts them in any order; progress stays in this browser until the file is complete.

…

Import photos, scans or a PDFBring in the whole document at once

Beam data with light

Transfer a file or text directly between two screens using QR frames and a camera. No Wi-Fi, internet connection, account, or network pairing is required: one device displays the data and the other reads it. It can be slower than a network transfer, but works when a network is unavailable or unwanted.

This device

Privacy

An interrupted receive resumes only when the stream is identical, and Open streams are: the same file always produces the same frames. A sealed one draws a fresh salt each time, so it is a new stream and starts over — that is the encryption doing its job.

Anything on a screen is readable by any camera pointed at it, so Open means open. Passphrase seals the file before it leaves (AES-256-GCM, key from PBKDF2, 250k rounds) and needs nothing from the other device — but the phrase has to travel some other way. Paired needs both cameras: the two ends swap keys optically, agree on one nobody typed, and each shows five emoji derived from both halves. If the emoji match, nothing sat in the middle.

Speed

Code size

Frames a second

Nothing is ever asked for twice, so these are free to guess wrong: every frame is a fresh combination of the file rather than one piece of it, and the receiver rebuilds from whichever ones land. Dropped frames cost seconds, never the file. Push both up until the other device stops keeping pace, then come back one step.

Camera

Start, stop and the file itself all live at the top of this tab, beside the code — nothing here needs scrolling back to mid‑transfer.

Nothing to beam yet

Text to beam

Both screens should show

Brightness

100%

A screen at full brightness can blow out the camera reading it. Ease this down while the transfer runs and watch the rate above: the right setting is the one where frames a second and KB/s stop climbing.

Incoming

Working…

Tap anywhere outside the code to close it.

Brightness

100%

If a camera is struggling to read this, dim it. A bright screen glares; most phones lock on faster a little way down.

That is the dense end of the dial

At 0.3 mm the white gaps between the squares are 0.3 mm as well, and most laser printers spread toner far enough to close them. The page looks right coming out of the tray and reads back as noise.

One calibration sheet is cheaper than a ream. It prints the same code at nine sizes and tells you the smallest your own printer and camera will agree on.

And if the point is only to get the file onto another device, the file already travels. Printed QR pages are one option when you want a file stored on paper rather than on a device.

Useful information should be easy to move

Hardcopy is a small collection of QR tools built to work locally in your browser. Make a code for something simple, read codes from a camera or image, move a file through printable pages, or send data from one screen to another using light.

No account or upload is needed for these workflows. Your information stays on your device while you work, and the app can run offline once the file is available locally. Choose the format that fits the job: a quick code to share, a tangible archive, or a direct screen-to-screen transfer.

Built independently by one person, with a focus on practical tools that stay useful without depending on a service staying online. If you find it useful, you can help support its continued development.

Tools like that exist because somebody decides to make them. This one is one person’s late nights, test prints and toner. If it earned its keep, there’s a tip jar at Duh — named for how obvious a good idea looks once someone has already gone and built it.

Support on Patreon