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Why Won't My QR Code Scan With a Logo? Fix It With Error Correction
You added a logo to the middle of a QR code and now a phone camera hesitates or refuses to read it. The fix almost always comes down to one setting: error correction. Here's how it works, how much of a code a logo can safely cover, and how to build a WiFi, vCard, or URL QR code that keeps scanning reliably.
How error correction (ECC) keeps a logo from breaking the scan
Short answer: Yes, a QR code can still scan with a logo on it — but only if the error-correction level is high enough. Set ECC to Q or H before adding a logo, keep the logo to roughly 20-25% of the code's area, and test the result on a real phone before printing anything.
QR codes are built with redundancy on purpose. The pattern encodes extra "backup" data alongside the actual content, so a scanner can still reconstruct the full message even if part of the code is dirty, torn, or covered by a logo. That redundancy level is called the error-correction level (ECC), and it comes in four tiers defined by the QR standard.
Error correction (ECC): a setting on every QR code that trades data capacity for damage tolerance. A higher ECC level means the code can lose more of its pattern and still be read correctly, at the cost of a denser, more complex-looking code for the same content.
QR code error-correction levels
Level
Approx. tolerance
Best for
L
~7%
Maximum data, clean digital display, no logo
M
~15%
General-purpose default, no logo
Q
~25%
Small logo, light print wear expected
H
~30%
Logo overlay, posters, packaging, outdoor signage
Say you're printing a table-tent QR code for a restaurant menu, with the restaurant's small circular logo in the center — this is a hypothetical example, not a guarantee for every case. At ECC level H, the code has enough spare redundancy that a logo occupying about a fifth of the pattern typically leaves plenty of margin for a phone camera to still resolve the full underlying data, even at an angle or in dim light. At ECC level L, the same logo could genuinely break the scan because there's little redundancy left to lose.
Rule of thumb: logo up to ~20-25% of the code area, ECC set to Q or H, sufficient contrast between the code and its background, and a real-device test before you commit to print. A generator that warns you automatically when ECC is too low for a logo saves a failed print run.
Which QR code type fits your situation
Short answer: Match the QR type to what you want the scan to do — a URL for a link, WiFi for network access, vCard for a contact card, and dedicated modes like email, SMS, phone, location, or calendar event for a one-tap action.
Beyond the logo question, picking the right underlying data type matters just as much. A WiFi QR code encodes the network name, password, and security type in a standard format, so scanning it prompts "Join this network?" instead of making a guest type a password by hand — including correct escaping of special characters and support for hidden (non-broadcast) networks. A vCard QR code puts a full contact card — name, phone, email, company, title — behind a single scan, and most phones offer "Add Contact" immediately, which is a natural fit for a printed business card.
Other modes solve narrower jobs well: an email-mode code opens a draft with a recipient, subject, and message pre-filled; an SMS or phone-mode code sets up a text or a one-tap call; a location-mode code opens the maps app at a specific coordinate; and an event-mode code offers to add a meeting or event straight to a calendar app, with a title, time, and location already filled in.
PNG or SVG — which file to download
Short answer: Use PNG for screens — web pages, social posts, slides. Use SVG for anything printed at scale, since it's a vector format that stays sharp no matter how large it's reproduced.
Use case
Format
Why
Website, social media, slides
PNG
Universally supported, ready for screens
Posters, signage, packaging, print shops
SVG
Vector — no blur at any size
Business cards
SVG
Print shops generally prefer vector files
Also worth knowing: codes generated with data written directly into the pattern (rather than through a paid redirect service) are static. They never expire, have no scan limit, and keep working even if the site that generated them ever goes offline — the tradeoff is that you can't edit the destination after printing, since there's no server in the loop to redirect through.
Build your own WiFi, vCard, or URL QR code — free, no sign-up, nothing leaves your browser.
Yes, but you need a higher error-correction (ECC) level. QR codes are built with redundancy so they still scan even if part of the pattern is damaged or covered. The highest level, H, tolerates roughly 30% of the code being obscured, which is the space a small logo can occupy. Set ECC to Q or H when adding a logo, keep the logo to at most 20-25% of the code area, and always test the result before printing.
Does a QR code I generate here expire, and is it free?
No. Codes made this way are static QR codes: the content is written directly into the code pattern itself, so they never expire and have no scan limit, and they'll keep working even if the website that made them ever goes offline. Generating one is free, with no account required.
How do you make a WiFi QR code with a hidden network?
Select the WiFi mode, type the network name (SSID) exactly, enter the password, choose the security type (most networks are WPA/WPA2), and check "Hidden network" if the SSID isn't broadcast. The tool encodes the standard WIFI:T:WPA;S:...;P:...;; format and escapes special characters like semicolons and backslashes automatically, so the code won't break.
Should I download a PNG or an SVG for printing a QR code?
A high-resolution PNG is fine for web, social media, and on-screen use. For signage, posters, packaging, or professional print jobs, an SVG is the better choice: it's a vector format that scales to any size without blurring, and most print shops prefer it.
Is my data sent to a server when I generate a QR code?
No, not with a client-side tool. QR code generation can run entirely in the browser, meaning the WiFi password, contact details, or text you enter is never sent to or logged on a server — it disappears the moment you close the page.
Methodology note: the guidance above reflects the general behavior of the QR Code (ISO/IEC 18004) standard's error-correction tiers and common print practices. Any numeric example in this article is illustrative, not a guarantee for a specific logo, printer, or scanner — always test a printed or displayed QR code with more than one device before relying on it.