June 1, 2026
QR Code Error Correction Levels: L, M, Q, H Explained
Every QR code has four error correction levels to choose from: L, M, Q, and H. Each level trades size for reliability. Choosing the right level is important for ensuring your QR code scans reliably throughout its lifetime.
This guide compares the four levels in detail and helps you choose the right one.
Level Comparison
Level L (Low — 7% Recovery)
| Factor | Detail |
|---|---|
| Recovery | ~7% of codewords |
| Best Use | Digital-only, controlled printing |
| Size | Smallest |
| Reliability | Lowest |
| Logo Compatible | No |
Level L is suitable when the QR code will never be printed or will be printed in a perfectly controlled environment. Digital QR codes on screens don't experience wear, so minimal error correction is sufficient.
Choose Level L when:
- QR code displayed on screen only
- Printed in pristine conditions (indoor, protected)
- Size must be as small as possible
- Data density is the priority
Level M (Medium — 15% Recovery)
| Factor | Detail |
|---|---|
| Recovery | ~15% of codewords |
| Best Use | General purpose |
| Size | Moderate |
| Reliability | Good |
| Logo Compatible | Marginal |
Level M is the default for most QR code generators. It balances size and reliability for typical indoor use.
Choose Level M when:
- General printed materials (flyers, brochures)
- Products with clean packaging
- Indoor signage
- Standard business cards
Level Q (Quartile — 25% Recovery)
| Factor | Detail |
|---|---|
| Recovery | ~25% of codewords |
| Best Use | Logos, outdoor, moderate wear |
| Size | Larger |
| Reliability | High |
| Logo Compatible | Yes |
Level Q is the recommended minimum for QR codes with logos. The logo typically covers 15-20% of the code, and level Q's 25% recovery provides a safety margin.
Choose Level Q when:
- Adding a logo to the QR code
- Outdoor signage (some weather exposure)
- Products that will be handled
- Menu cards in restaurants
Level H (High — 30% Recovery)
| Factor | Detail |
|---|---|
| Recovery | ~30% of codewords |
| Best Use | Harsh environments, max durability |
| Size | Largest |
| Reliability | Highest |
| Logo Compatible | Yes (with space) |
Level H provides the maximum possible error correction. Use it when reliability is critical and size is not a constraint.
Choose Level H when:
- Industrial environments
- Long-term outdoor signage
- Products exposed to harsh conditions
- Medical or safety applications
- Permanent installations
Size Trade-Off Visualization
For a URL with 40 characters:
| Level | QR Size | Modules |
|---|---|---|
| L | Version 3 | 29 × 29 |
| M | Version 3 | 29 × 29 |
| Q | Version 4 | 33 × 33 |
| H | Version 4 | 33 × 33 |
For a URL with 100 characters:
| Level | QR Size | Modules |
|---|---|---|
| L | Version 4 | 33 × 33 |
| M | Version 5 | 37 × 37 |
| Q | Version 6 | 41 × 41 |
| H | Version 6 | 41 × 41 |
Practical Recommendations
| Use Case | Recommended Level | Why |
|---|---|---|
| Digital display (screen) | L | No wear, smallest size |
| Print flyer | M | Standard durability |
| Business card | M | Small size preferred |
| QR code with logo | Q | Logo covers ~20% |
| Product packaging | Q | Handling damage |
| Outdoor sign | Q or H | Weather exposure |
| Industrial equipment | H | Harsh conditions |
| Menu (restaurant) | Q | Frequent handling |
Creating QR Codes with Specific Levels
Use a free QR code generator that offers all four error correction levels:
- Enter your URL or text
- Select the error correction level (L, M, Q, or H)
- Customize design
- Generate and test with intentional damage
Conclusion
Level M is the safe default for most use cases. Choose Level Q if you need a logo or outdoor durability. Level H for maximum reliability. Level L only for digital-only applications.
Generate QR codes with your preferred error correction level — choose L, M, Q, or H for your specific use case.