Do the QR codes expire or stop working?

No. The code encodes your text or link directly, with no redirect service in the middle, so there is nothing to expire, no tracking, and no account that could stop working later.

What is error correction and which level should I pick?

Error correction lets a scanner read the code even when part of it is damaged or covered. Level L recovers about 7% of the code, M about 15%, Q about 25% and H about 30%. M is a good default, and H is worth it for printed codes or when you place a logo over the centre.

Why does my QR code look denser after I edit the text?

Longer content needs a larger QR version, which means more modules in the same square. Denser codes need a better camera or a closer scan, so keep links short if the code will be printed small.

Should I download PNG or SVG?

PNG for screens, chat and documents. SVG for print and large signage, because it is a vector and stays sharp at any size.

How large should a printed QR code be?

A common rule of thumb is a code width of about one tenth of the scanning distance, so a code read from one metre away wants to be roughly ten centimetres across. Test with a phone before printing a run.

Is anything sent to a server?

No. The code is generated in your browser, so the link or text you encode is never transmitted or logged.

QR code generator

Turn a link or any text into a QR code, then download it as a PNG for screens or an SVG for print. The code holds your content directly, so there is no redirect service in the middle, nothing to expire and no tracking. Free, no signup, generated in your browser.

Link or text

A full address starting with https opens the site. Plain text is shown to whoever scans it.

Error correction

Higher recovery survives more damage but makes the code denser.

PNG size

The SVG is a vector, so it stays sharp at any size.

This code

Version 2, 25 by 25 modules, error correction M. It holds 19 bytes of the 28 this version allows at that level, which is 68% full.

Scan it with your phone camera before you use it anywhere. That is the only test that counts.

Runs on your device. The code is encoded in this tab, right down to the error correction maths. The link you type is never sent anywhere, which is not true of generators that wrap your address in a redirect they own.

How to choose an error correction level

A QR code carries spare data so a scanner can still read it when part of the code is dirty, torn or covered. The four levels recover roughly 7%, 15%, 25% and 30% of the code.

M is the sensible default for a screen or a document. Q or H earn their extra density on anything printed, anything that will live outdoors, and anything with a logo placed over the middle, since that logo is damage as far as the scanner is concerned. L is worth it only when the content is long and the code has to stay readable at a small size.

Why the code gets denser as you type

A QR code comes in versions, from 1 at 21 modules square up to 40 at 177. The generator picks the smallest version that fits your content at the error correction level you chose, so a longer link means more modules in the same square, and each module gets smaller.

That matters when the code will be printed small. If your code has gone dense, shorten the address, drop the tracking parameters, or use a shorter domain. It is the single most effective thing you can do for scan reliability.

Printing a QR code so it actually scans

Three things decide whether a printed code works. Size: a common rule of thumb is a code width of about one tenth of the distance it will be scanned from, so one metre away wants roughly ten centimetres across. Contrast: dark code on a light background, never the reverse, and never on a busy photograph.

Quiet zone: the empty margin around the code is part of the code. The downloads here include it, so do not crop the file tight to the pattern. Then test the printed proof with two different phones before the run.

Frequently asked questions

Do the QR codes expire or stop working?: No. The code encodes your text or link directly, with no redirect service in the middle, so there is nothing to expire, no tracking, and no account that could stop working later.
What is error correction and which level should I pick?: Error correction lets a scanner read the code even when part of it is damaged or covered. Level L recovers about 7% of the code, M about 15%, Q about 25% and H about 30%. M is a good default, and H is worth it for printed codes or when you place a logo over the centre.
Why does my QR code look denser after I edit the text?: Longer content needs a larger QR version, which means more modules in the same square. Denser codes need a better camera or a closer scan, so keep links short if the code will be printed small.
Should I download PNG or SVG?: PNG for screens, chat and documents. SVG for print and large signage, because it is a vector and stays sharp at any size.
How large should a printed QR code be?: A common rule of thumb is a code width of about one tenth of the scanning distance, so a code read from one metre away wants to be roughly ten centimetres across. Test with a phone before printing a run.
Is anything sent to a server?: No. The code is generated in your browser, so the link or text you encode is never transmitted or logged.

A QR code shares the material. FORKSAI helps you learn it.

Turn the notes, slides and PDFs behind that link into flashcards and spaced repetition sessions.

The tool above stays free and needs no account.

More free tools

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There are study calculators too, on the free student tools hub.

Plan your next review session

Use the free student study kit to plan a week of revision, check flashcard quality, and record mistakes from practice questions.

Need a deck first? Turn a lecture PDF into editable flashcards, then follow the active recall guide to practise answering before revealing the back of each card.

Working toward an exam? Build a daily target with the exam study planner, protect the session with the Pomodoro study timer, or check your current result with the weighted GPA calculator.