QR code versions 1 to 40 — sizes, capacity and how to choose

QR codes come in 40 versions. Version 1 is 21×21 modules and each version adds 4 modules per side, up to 177×177 at version 40, which holds up to 2,953 bytes. Generators auto-select the smallest version that fits the payload at the chosen error-correction level — and smaller scans better.

The 40 sizes

A QR code's version is its size class, nothing more. The rule is one line:

side length in modules = 4 × version + 17

Version 1 is 21 × 21; every step adds 4 modules per side; version 40 is 177 × 177 — 31,329 modules. Capacity grows faster than area suggests, because the fixed overhead (finders, timing, format bits) is bought once: at version 1 function patterns consume 53% of the symbol, at version 40 under 9%.

Milestones (byte capacity at level M):

Version	Modules	Bytes at M
1	21 × 21	14
2	25 × 25	26
5	37 × 37	84
10	57 × 57	213
40	177 × 177	2,331

The ceiling at version 40, level L, is 7,089 numeric / 4,296 alphanumeric / 2,953 bytes. Full per-version figures are in the capacity table and the version and module table.

Structural features arrive on a schedule too: alignment patterns from version 2, the explicit version information field from version 7.

How the version is chosen

You normally do not choose it. Encoders — UseQR's included — take the payload and the error-correction level and select the smallest version whose capacity holds the encoded bit stream. Three inputs move the outcome:

Payload length — the dominant factor.
Encoding mode — 100 digits fit in far fewer bits than 100 arbitrary bytes.
EC level — raising L → H roughly halves data capacity at a given version, pushing the payload into a bigger symbol.

Measured with UseQR's encoder: a 71-character URL needs version 5 (37 × 37) at level M but version 8 (49 × 49) at level H. Same data, 44% more modules — each one smaller at the same printed size.

Why smaller is better

Every version step makes modules smaller at a fixed physical size, and module size is what limits scan distance and camera focus. A version 3 code scans from further away, survives worse printing and forgives more styling than a version 12 code at the same footprint. The practical ordering:

Shorten the payload (a short URL can drop several versions).
Set the EC level the environment needs — not more.
Let the version fall where it falls, then size the print for the distance.

Forcing a higher version than needed is occasionally useful — batches where every code must be the same size regardless of payload — and UseQR's API accepts a version parameter for exactly that. Forcing a lower one is impossible: if the data does not fit, generation fails rather than silently truncating.

FAQ

What do QR code versions mean?

Version is the symbol's size class, from 1 (21×21 modules) to 40 (177×177). Each version adds 4 modules per side and therefore more capacity. It has nothing to do with software versions or the age of the standard.

Which QR code version should I use?

The smallest one that fits your payload at your chosen error-correction level — which is what generators select automatically. Lower versions have larger modules at the same printed size, so they scan from further away and tolerate more damage.

How much data does a version 40 QR code hold?

At error-correction level L: 7,089 numeric digits, 4,296 alphanumeric characters, or 2,953 bytes. At level H that falls to 1,273 bytes. In practice codes that large are hard to scan from print and are rarely a good idea.

How do I find a QR code's version?

Count the modules along one edge and compute (count − 17) ÷ 4. A 29-module side is version 3. Decoders do the same measurement via the timing patterns, cross-checked against the version information field from version 7 up.