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QR Code Generator

Turn a URL or text into a QR code instantly and download it as PNG — free.

Error correction is not a simple size dial

The same URL encoded at all four correction levels, PNG bytes measured.

Input
https://yunknow.cc/
Output
L (low)       3403 bytes
M (medium)    3353 bytes
Q (quartile)  3382 bytes
H (high)      4206 bytes

The obvious expectation is that more error correction means a bigger file. It does not hold: M came out smaller than L (3353 vs 3403 bytes). Higher correction adds redundancy, but the encoder can also land on a different mask pattern that compresses better — only H, which needs a denser grid, is clearly the largest at 4206. Pick a level for how the code will be used, not for file size: H survives a scuffed printout, L does not.

Online QR code generator

QR codes turn a URL, text or contact details into an image any phone can scan — useful for business cards, posters, menus and event links. This free QR code generator creates one instantly, lets you download a PNG, and runs entirely in your browser with no uploads.

How to use

  1. Paste a URL or any text into the box.
  2. Adjust the error-correction level if needed.
  3. The QR code appears live; click Download PNG to save it for print or sharing.

Common use cases

  • Put a website or event link on a poster or business card.
  • Restaurant digital menus and Wi-Fi sharing.
  • Turn a long URL into a scannable image.

Before you print that QR code, scan it yourself

Turning a link, your café's Wi-Fi login, or your contact details into a QR code for a poster, menu, or business card is the everyday use case here. A few things trip people up, though. Always scan the finished code with a real phone before you send it to print and confirm it opens and lands on the right page. The longer the URL, the denser the grid becomes and the harder it is for a camera to read, so run it through a URL shortener first. And if you plan to drop a logo in the middle or print it small, bump up the error-correction level so a bit of damage or smudging won't stop it from scanning.

What does choosing error-correction level H cost?

We encoded the same URL at all four levels and measured the PNG each time: L 3403 bytes, M 3353 bytes, Q 3382 bytes, H 4206 bytes. Interestingly M and Q came out smaller than L — the redundancy did not push the code into a larger version, and at the same module count a denser pattern compresses better. Only H needed a bigger grid. The real cost is not bytes but module size at a given printed width: either more paper, or a closer scan.

Frequently Asked Questions

Do the generated QR codes expire?

No. These are static QR codes — the content is encoded directly into the image, so they never expire and have no scan limits or tracking.

Is my data uploaded?

No. The QR code is generated entirely in your browser; the URL or text you enter is never sent to a server.

What is the error-correction level?

The level (L/M/Q/H) controls how much of the code can be damaged or obscured while still scanning. Higher is more robust but denser. M is a good default.

Related reading

How to Create a QR Code (Free): A Practical Guide →

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