Free QR Code Generator - Create Scannable QR Codes

What Is a QR Code Generator?

A QR code generator is a tool that turns text, such as a web address, into a QR code: a square pattern of black and white squares. A phone camera or barcode scanner reads the pattern and recovers the original text almost instantly.

How This Tool Encodes Text

Type text or a URL into the input box. The tool converts every character to its UTF-8 byte values and encodes them using "byte mode," one of the ways the QR code standard, ISO/IEC 18004, stores data. It builds the code at error-correction level M, the standard's second of four correction levels, and picks the smallest of the 40 possible QR code sizes, called versions, that can hold the input. It then tests eight fixed patterns, called masks, and keeps the one that spreads dark and light squares most evenly, which makes the code easier for a scanner to read. The QR code updates automatically after a short pause in typing.

This tool always uses byte mode and error-correction level M. It does not offer a numeric or alphanumeric mode, a Kanji mode, or a choice of correction level.

How to Calculate QR Code Capacity

A QR code version's capacity depends on its total codewords (groups of 8 bits) and how many of those codewords are set aside for error correction.

data codewords = total codewords − error-correction codewords

The number of bits a piece of byte-mode text needs is:

needed bits = 4 + character-count bits + 8 × number of bytes

The 4 bits identify the encoding mode. The character-count field is 8 bits for versions 1 through 9, and 16 bits for versions 10 and up. The tool checks each version from 1 to 40 in order and uses the first one whose data capacity, in bits, is large enough.

Example

The text "https://whiz.tools" is 18 characters, all plain letters and symbols, so it becomes 18 bytes.

Version 1 (21×21 squares) at level M has 16 data codewords, or 128 data bits. The text needs 4 + 8 + (8 × 18) = 156 bits, so it does not fit.

Version 2 (25×25 squares) has 28 data codewords, or 224 bits. The same 156 bits fit, so the tool builds a version 2 code for this text.

Error Correction and Masking

Error-correction level M lets a QR code stay readable even if part of it is smudged, torn, or covered, up to roughly 15 percent of its data, by adding extra codewords calculated with Reed-Solomon error correction. Level M is one of four levels: level L restores about 7 percent of codewords, M about 15 percent, Q about 25 percent, and H about 30 percent. This tool always builds at level M.

Once the data sits in the grid, the tool tries all eight standard mask patterns. Each one is scored by counting features that confuse scanners, such as long runs of the same color, solid blocks, patterns that look like a corner finder square, and an uneven mix of light and dark squares. The tool keeps the mask with the lowest score.

How to Use This QR Code Generator

1. Type or paste text, a web address, or another short message into the input box.
2. The QR code appears below the box a moment after typing stops.
3. Select "Download QR Code" to save the image as a PNG file.
4. Select "Reset" to clear the box and start over.

The input box accepts up to 500 characters. The text is also stored in the page's web address, so sharing that link reproduces the same QR code for anyone who opens it.

What This Tool Does Not Do

The generator does not offer a choice of error-correction level, custom colors, a logo overlay, or an SVG export. The only download format is PNG.

Quiet Zone and Image Size

A QR code needs a blank border, called the quiet zone, that is four modules wide on every side. A module is one square of the code. Without this border, a scanner can fail to find where the code starts.

The tool always draws the code with this border. It places the code in the center of a 250 × 250 pixel image. Each module is a whole number of pixels, so that its edges stay sharp. The module size is:

cell size = floor(250 ÷ (modules per side + 8))

The 8 adds four modules of border on each side. "floor" means rounding down to a whole number. Rounding down leaves some extra white space, so the border is never less than four modules.

For "https://whiz.tools", the version 2 code is 25 modules wide. The cell size is floor(250 ÷ 33) = 7 pixels. The code itself is 175 pixels wide, which leaves 37 to 38 pixels of white on each side, more than the 28 pixels that four modules need.

The largest code the 500-character input can produce is version 32, at 145 modules per side. Its modules are 1 pixel each. When printing a code or placing it on a colored background, keep the white border in place.

History

DENSO WAVE, then a division of the Japanese car-parts maker DENSO, released the QR code in 1994. The car industry adopted it early to track parts in production. The name stands for "quick response", because a scanner can read it quickly. The QR code was approved as the international standard ISO/IEC 18004 in 2000. The standard has since been revised, and this tool follows the 2015 edition. Camera phones with built-in QR scanning later made the format common, and contactless menus and payment codes during the COVID-19 pandemic made it familiar to far more people.

Common Uses of QR Codes

QR codes commonly appear on:

• Restaurant tables, linking to a digital menu
• Product packaging, linking to instructions or ingredient details
• Posters and business cards, linking to a website or contact page
• Wi-Fi network cards, when the text is formatted in a way scanners recognize
• Event tickets and boarding passes, for fast check-in scanning

Frequently Asked Questions

What is the maximum amount of text this QR code generator can encode?

The input box accepts up to 500 characters. The QR code standard allows far more: a version 40 code at error-correction level M, the level this tool uses, can hold 2,331 bytes.

Why does the QR code get bigger for longer text?

A QR code stores data in a fixed grid of squares. Longer text needs more codewords, so the tool switches to a larger version, meaning more rows and columns, whenever the current version cannot fit the input.

Can this tool add a logo or custom color to a QR code?

No. It draws black squares on a white background and does not support logos, custom colors, or SVG export. The download is always a PNG image.

Does a QR code expire?

No. The code stores the exact text entered when it was made. If that text is a web address, the code stops being useful only if the address stops working; the image file itself does not expire.

Is a damaged or partly covered QR code still readable?

Often yes. Error-correction level M, which this tool always uses, can restore roughly 15 percent of the codewords if they are missing or unreadable, as long as the three corner squares stay intact.

What is the difference between a QR code and a regular barcode?

A standard barcode stores data in one direction and typically holds a few dozen digits. A QR code stores data across both rows and columns, so it can hold thousands of characters in the same space, and it includes built-in error correction that ordinary barcodes lack.

References

1. DENSO WAVE. Information capacity and versions of QR Code (Versions 1–10). QR Code versions 1–10 — data bits per version and level (Version 1, level M: 128 bits; Version 2, level M: 224 bits).
2. DENSO WAVE. Information capacity and versions of QR Code (Versions 31–40). QR Code versions 31–40 — Version 40, level M holds 2,331 bytes in binary (byte) mode.
3. DENSO WAVE. QR Code Standardization. QR Code standardization — error-correction levels L, M, Q, H restore about 7, 15, 25 and 30 percent of codewords; ISO/IEC 18004 approval in June 2000.
4. DENSO WAVE. Point for determining the code area. QR Code size and quiet zone — a four-module quiet zone on all sides.
5. DENSO WAVE. History of QR Code. QR Code history — released in 1994; "QR" stands for quick response; ISO approval in 2000.