I work on OnePassApps, the team behind app.onepassapps.com, so this is about a tool we ship. Everything below is what the live tab printed when I ran it today - not a description of how a QR generator ought to behave.
Our QR Code Maker is one of the browser-local apps: the code is drawn in the tab and the file lands on your own machine. The page's own opening line is:
Make a static QR code for a link, text, Wi-Fi, contact, email, phone or SMS, then download it as PNG or SVG.
What you set before a code appears
The panel has two numbered stages. 01 Content opens on a Type control that ships on Link, with a field whose placeholder is https://example.com and the hint "Starts with http or https. https:// is added if you leave it out."
02 Appearance is where the interesting numbers live:
- Error correction has four levels - L, M, Q, H - under the line "Level M can recover about 15% of a damaged code. Higher levels make a denser code."
- Module scale is a field labelled "Module scale in pixels", shipping at 10, with the hint "Pixels per module."
- Quiet zone is a field labelled "Quiet zone in modules", shipping at 4, with the hint "Modules around the code."
-
Foreground and background ship at
#111111on#ffffff, and the panel prints the resulting ratio: "Contrast is 18.9:1, which suits scanners."
The stage heading under Appearance is the promise the rest of the panel keeps: "Nothing leaves this tab."
What the panel prints once the content is complete
I put a real URL in the content field - https://app.onepassapps.com/guides/qr-code-maker, 48 characters - and the preview appeared with a details block under it. Read straight off the page:
| Detail | Value |
|---|---|
| Version | 4 of 40 (33 × 33) |
| Error correction | M, recovers about 15% |
| Data mode | byte |
| Capacity used | 48 bytes · 77% of 64 data bytes |
| Mask | 2 |
| PNG size | 410 × 410 px |
The preview heading reads "Version 4 · 33 × 33 modules", and under ENCODED CONTENT the panel echoes the URL back so you can confirm you encoded what you meant to encode.
The PNG, read back off disk
I pressed Download PNG and then read the file that actually landed on disk: 6,352 bytes, a 410 × 410 PNG. That matches the panel's own PNG size figure, and it is also what the geometry predicts - a version 4 code is 33 × 33 modules, the quiet zone adds 4 modules on each side (33 + 8 = 41 modules), and at 10 pixels per module that is 410 pixels square. The quiet-zone setting is not decoration; it is in the byte count of the file you download.
What I did not test
- I left the error-correction level on its shipped M, so "Higher levels make a denser code" is the panel's copy here, not a measurement of mine.
- I captured the PNG only. The panel also offers "Download SVG"; I did not read that file's bytes.
- One URL, one browser, one build, 6 November 2026.
Try it
The tool needs no account, and the code is static - the content is inside the image, so it keeps working without us. The page puts it plainly: "Static code: the content is in the image itself, so it keeps working without us."
If you want the short walkthrough, the OnePassApps guides page has it.
One line from the panel is worth repeating before you print anything: "Always test a printed or on-screen code with the phones and apps your audience uses."
I work on OnePassApps - we make the browser apps behind app.onepassapps.com, and every figure above came from running the live tool today.
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