Ever noticed that some QR Codes are tiny while others look like a massive maze? That's not a design choice — it's physics: more data means more modules (the little squares), which means a bigger code. Understanding this saves you from nasty surprises at print time.
This guide covers the 40 versions of the QR Code standard, the historical models, special variants, and content types — URL, Wi-Fi, vCard — with a reference table and a step-by-step on how the generator picks the right version.
The 40 QR Code versions
The QR Code standard (ISO/IEC 18004) defines 40 versions, numbered 1 through 40. Each version is a square grid of modules:
- Version 1 → 21×21 module grid (the smallest possible)
- Version 40 → 177×177 module grid (the largest in the standard)
The formula is simple: modules = 17 + (version × 4).
The more data you encode, the higher the version the generator chooses — and the visually larger and denser the QR becomes.
Reference table: version → modules → capacity
| Version | Grid (modules) | Approx. capacity (alphanumeric, level M) |
|---|---|---|
| 1 | 21×21 | ~20 characters |
| 2 | 25×25 | ~38 characters |
| 5 | 37×37 | ~85 characters |
| 10 | 57×57 | ~271 characters |
| 15 | 77×77 | ~535 characters |
| 20 | 97×97 | ~858 characters |
| 25 | 117×117 | ~1,269 characters |
| 30 | 137×137 | ~1,754 characters |
| 35 | 157×157 | ~2,313 characters |
| 40 | 177×177 | ~4,296 characters (numeric) / ~2,953 alphanumeric |
Practical tip: a typical short URL (
https://code2scan.com/p/abc123) has ~34 characters — it fits comfortably in version 2 or 3. A long URL with UTM parameters can push you to version 6 or 7.
Want to dig deeper into capacity limits? Check the article on QR Code data capacity.
Model 1 vs Model 2
Before the modern standard there was Model 1, created by Denso Wave in 1994. Model 2 (1997) is what we use today — and what phone scanners recognize. Key differences:
| Feature | Model 1 | Model 2 (current) |
|---|---|---|
| Maximum capacity | Lower | Much higher (v40) |
| Alignment | Simple | Additional alignment patterns |
| Error correction | L, M, Q, H | L, M, Q, H (improved) |
| Phone scanning | Rare support | Universal |
In practice: forget Model 1. Every modern generator uses Model 2.
Micro QR Code
Micro QR Code is a compact variant with only 4 versions (M1 to M4) and a minimum 11×11 module grid. It was designed for industrial labels, electronic components, and spaces where a standard QR Code won't fit.
| Version | Grid | Maximum capacity |
|---|---|---|
| M1 | 11×11 | 5 numeric digits |
| M2 | 13×13 | 10 numeric / 6 alphanumeric |
| M3 | 15×15 | 23 numeric / 14 alphanumeric |
| M4 | 17×17 | 35 numeric / 21 alphanumeric |
When to use: only when space is critical and content is very short (a batch code, a numeric ID). For URLs, always use a standard QR Code.
Special variants: iQR, SQRC and Frame QR
Beyond the ISO standard, Denso Wave created proprietary variants:
- iQR Code — supports rectangular grids and capacity well beyond v40. Rarely supported by consumer apps.
- SQRC (Secure QR Code) — has a private data layer that only authorized readers can access. Used in industrial access control.
- Frame QR — reserves a central "canvas" for an image, logo, or animated text. Some generators offer something similar with an overlaid logo.
For everyday use (marketing, business, links), the standard Model 2 QR Code covers 99% of cases.
Content types: what goes inside the QR
Beyond technical versions, there is a classification by content type — which is what most people mean when they say "type of QR Code":
| Type | What it stores | Tool |
|---|---|---|
| URL / Link | Web address (most common) | QR Generator |
| Text | Free text, no link | Text QR |
| Wi-Fi | SSID, password, security type | Wi-Fi QR |
| vCard | Name, phone, email, company | vCard QR |
| Number + pre-filled message | WhatsApp QR | |
| Recipient + subject + body | Email QR | |
| SMS | Phone number + message text | SMS QR |
Each type formats the data in a specific way (protocols like WIFI:, mailto:, BEGIN:VCARD) before generating the QR. The generator handles this automatically.
Error correction levels affect the version
QR Code has 4 error correction levels (L, M, Q, H) that define how much of the code can be damaged and still be read. Level H offers the most protection — but uses more modules, pushing you to a higher version.
| Level | Recovers up to | Impact on size |
|---|---|---|
| L | 7% | Smallest QR |
| M | 15% | Balanced (default) |
| Q | 25% | Larger |
| H | 30% | Largest (required when overlaying a logo) |
Learn more in the article on QR Code error correction.
How the generator picks the version (step by step)
You don't need to choose a version manually — the generator does it for you. Here's the process:
- You provide the content — a URL, text, Wi-Fi credentials, etc.
- The generator counts the characters and identifies the encoding mode (numeric, alphanumeric, byte, kanji).
- It applies the chosen correction level (default: M).
- It calculates the minimum version that fits everything.
- It generates the QR at that version — no bigger, no smaller.
If you shorten the URL (using a link shortener), the generator may use a lower version → a cleaner, easier-to-scan QR. Find out more about what a QR Code is and how the standard works.
Why the QR gets bigger when you add data
Each extra module costs space. A QR Code can't simply "squeeze" more data into the same grid — it would have to shrink each module to the point of making scanning impossible. That's why the spec defines higher versions: more modules = more data = bigger QR.
Adding a logo, raising the correction level, using a long URL, or including special characters are the main factors that push the version up.
Common mistakes
❌ Thinking a high version means a bad QR
Version 10, 15, 20 — all perfectly normal. What matters is that the QR is printed at the right size for the reading distance.
❌ Using Micro QR for URLs
Micro QR has very limited capacity. For links, always use standard QR Code (Model 2).
❌ Ignoring the correction level when adding a logo
If you place a logo in the center of the QR, use level H. Otherwise the data covered by the logo loses its redundancy and the code may fail.
❌ Printing the QR too small
A version 10 QR printed at 1 cm will fail. Respect the minimum print size for your reading distance.
❌ Confusing "QR type" with "QR version"
"Type" is the content (URL, Wi-Fi, vCard). "Version" is the grid size (1 to 40). They are different concepts.
Summary
- The standard QR Code has 40 versions (21×21 to 177×177 modules) — more data = higher version.
- Model 2 is the current standard; Model 1 is obsolete.
- Micro QR (M1–M4) is for very short content in minimal spaces.
- iQR, SQRC, and Frame QR are proprietary variants for specific uses.
- Content types (URL, Wi-Fi, vCard) are different categories from technical versions.
- The correction level (L/M/Q/H) affects size — use H if you add a logo.
- The generator picks the version automatically — your job is to provide the right content.
Generate your QR Code now — the generator automatically selects the ideal version for your content, with PNG, SVG, and PDF export.
