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QR error correction (L/M/Q/H): which one to choose (practical)

Pick the right error correction level for print/screens/logos. Learn the trade-off: higher correction = denser QR = needs larger print.

On this page
  1. What L / M / Q / H means
  2. The trade-off (this is why scans fail)
  3. Practical picks (fast rules)
  4. Make it scan reliably (checklist)
Quick steps
  1. Start with level M: M is a balanced default for most print and screen use cases.
  2. Increase size first: If scans fail at small sizes, print larger before raising correction.
  3. Use Q/H only when needed: Higher correction is for damaged prints or logos, but it adds density.
  4. Test the final print: Scan at the real distance on multiple phones.

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Error correction is why a QR code can still scan when it’s a bit dirty or blurred. But there’s a catch: higher correction usually makes the QR denser, which can hurt scanning if you print small.

What L / M / Q / H means#

These are common QR error correction levels. You can think of them as “how much damage the QR can tolerate”. Higher levels tolerate more damage, but typically increase complexity/density.

LevelPractical meaningWhen to use
LLowest tolerance, often lowest densityClean screens, large QR, short payload
MBalanced (good default)Most use cases
QHigher tolerance, usually denserPrints that may get worn / slightly blurry
HHighest tolerance, often densestIf you expect damage or add a logo (print larger)

The trade-off (this is why scans fail)#

  • Higher correction → more modules → denser QR → needs larger print and sharper edges.
  • If you print small (business cards/table tents), density matters more than tolerance.
  • If your payload is long (UTM, long URLs, big vCard), density increases fast. Prefer a shorter destination first.

Practical picks (fast rules)#

  • Business cards (20–25mm): start with M. If the print is glossy/low quality, increase size before jumping to H.
  • Posters/signage: Q is fine if you print large; H can work but print bigger and test.
  • QR with a logo: you may need Q/H, but the more important factor is size + quiet zone + sharp SVG print.
  • WiFi / vCard: payloads can get dense — keep fields minimal and print larger if needed.

Make it scan reliably (checklist)#

  1. Keep the payload short (see: Short URL strategy).
  2. Use SVG for print (see: SVG vs PNG).
  3. Keep quiet zone + high contrast (see: Contrast & quiet zone).
  4. Test on iPhone + Android before mass printing.

Continue reading

← Previous
Mailto QR code guide: QR code that opens email
Create a mailto QR code (email QR code) that opens an email draft with recipient, subject, and message — with examples and print tips.
Next →
QR for posters/signage: size by scan distance (print-ready table)
How big should a QR be on posters and signs? Use a simple distance→size table, plus placement and glare tips for real-world scanning.

Related guides

Printing
Use 20-25 mm (0.8-1.0 in) for most business cards. Includes minimum size guidance for short URLs, larger sizing for vCards, quiet zone rules, and a card dimensions chart.
How to add a QR code to a business card (visiting card) in Canva: generate the right QR (vCard vs URL), download SVG/PNG, keep a quiet zone, and export for print.
Canva QR code generator: create a URL QR in Canva, or generate vCard/WiFi/social QR codes with QRFlow and upload — plus print-ready export tips.
Short answer: usually yes for print. SVG stays sharp when resized, while PNG is fine for screens if exported large enough and never upscaled.
Why quiet zone is non-negotiable, how to choose colors that scan, and what backgrounds (patterns, gradients) break QR detection.
How big should a QR be on posters and signs? Use a simple distance→size table, plus placement and glare tips for real-world scanning.

Quick answers

Common questions

Which level should I start with?
Use level M as the default and size up if scans are slow.
When should I use level H?
Only if you expect damage or add a logo, and print larger.
What size should I print for reliable scans?
Use 20-25 mm for business cards and scale up for posters or distance scans.
Which download format is best for print?
Use SVG for crisp edges at any size. PNG is best for screens only.
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