QR & Barcode Tools
Four tools covering both directions of machine-readable codes: generating them and reading them back. QR codes and retail barcodes look related but solve different problems. A QR code is a two-dimensional matrix that carries arbitrary text — a URL, a Wi-Fi credential, a contact card, a UPI payment string — and includes error-correction data, so it still scans with a portion of the symbol damaged or obscured. A retail barcode is a one-dimensional stripe encoding a fixed-length number under a rigid standard: EAN-13 for products sold internationally, UPC-A in North America, Code 128 where you control both the printing and the scanner. The generators build the symbol in your browser and let you download it; the scanners decode an uploaded image or a camera frame. All four run locally, which matters more than usual here, because the content of a QR code is frequently a password or a payment identifier you would not want transmitted anywhere.
QR Code Generator
Create branded custom QR codes with gradient colors and center logos.
Barcode Generator
Generate EAN, UPC, Code128, Data Matrix, PDF417 and more.
QR Code Scanner
Scan QR codes online using your camera feed or image file upload.
Barcode Scanner
Scan retail tags or Code 128 shipping labels from webcam.
Recommended Workflows in QR & Barcode Tools
⚡ A code for a poster or a shopfront
Generate the QR with the destination URL -> download it as SVG or a large PNG so print does not soften the modules -> test with two different phones before the artwork goes to the printer.
⚡ Labelling stock you sell
Generate EAN-13 from your allocated product number, or Code 128 if the codes are only for internal use -> print at a size your scanner can resolve -> read one back with the scanner before printing the whole run.
⚡ Checking what a code you received actually contains
Photograph or screenshot the code -> decode it with the scanner -> read the destination before following it, since a printed QR gives no visual clue where it leads.
How to Choose the Right Tool
| If Your Task Is... | Recommended Tool | Action |
|---|---|---|
| A link, Wi-Fi network, phone number or UPI request needs a scannable code | QR Generator | Open Tool |
| Products need EAN-13, UPC-A or Code 128 stripes for a till or scanner | Barcode Generator | Open Tool |
| You have a photo or screenshot of a QR and want to know what it holds | QR Scanner | Open Tool |
| A product label needs reading and the digits underneath are worn away | Barcode Scanner | Open Tool |
| The finished code has to be placed onto a printed sheet or card | PVC Card Sheet Printer | Open Tool |
Best Practices & Practical Tips
- ✓Keep dark modules on a light background. Scanners look for that polarity, and while modern phone cameras often cope with inversion, older handheld and till scanners frequently do not.
- ✓Leave the quiet zone alone. A QR needs roughly four modules of clear margin on every side; cropping tight to the pattern is one of the most common reasons a code that looks fine will not scan.
- ✓Download SVG for print. Vector output stays crisp at any size, whereas a small PNG scaled up on a press leaves soft module edges that push the decoder's error correction to its limit.
- ✓Test with more than one phone, including an older one, before committing to print. A run of ten thousand flyers is an expensive place to discover a contrast problem.
- ✓Shorten the URL before generating, not after. Fewer characters means fewer modules, which means larger modules at the same physical size and a far more forgiving scan.
Common Mistakes to Avoid
- ⚠️Inverting the colours for aesthetic reasons — light modules on a dark background. It looks better in a layout and fails on a meaningful share of scanners.
- ⚠️Placing a logo over the centre without checking. Error correction can absorb a covered area, but only up to the level the code was generated at; past that, the symbol is simply broken.
- ⚠️Printing a QR too small for its viewing distance. A usable rule of thumb is a tenth of the distance it will be scanned from — a code read from two metres wants to be about 20 cm across.
- ⚠️Using a low-contrast colour pair such as mid-grey on beige. The decoder thresholds the image to black and white, and a narrow contrast range collapses under uneven lighting.
- ⚠️Encoding an EAN-13 with the wrong number of digits. The standard requires twelve digits plus a calculated check digit; an arbitrary number will render as a stripe pattern that no retail scanner accepts.
Frequently Asked Questions
How large should a QR code be when printed?
Scale it to about one tenth of the distance it will be scanned from. A code on a table tent read at 30 cm works at 3 cm across; one on a wall poster read from two metres needs roughly 20 cm. Denser content means more modules and each module gets smaller, so a long URL at a fixed physical size is harder to read than a short one.
Do QR codes generated here expire or need a subscription?
No. The code is a static image encoding your content directly — there is no redirect through ToolMela, no tracking, and nothing that can be switched off later. That also means the content is fixed: if the destination URL changes, you generate a new code. Services that let you edit a code after printing work by encoding a redirect they control, which is the trade-off you accept for that flexibility.
What is the difference between QR error-correction levels?
They set how much of the symbol can be damaged and still decode: roughly 7 percent at level L, 15 at M, 25 at Q, and 30 at H. Higher correction adds modules, so the code becomes denser at the same physical size. Level M is the usual compromise; H is worth it when a logo overlays the centre or the code is printed somewhere it will be scuffed.
Which barcode standard should I use?
If products are sold through retailers, you need EAN-13 or UPC-A with a number issued to you by GS1 — inventing digits produces a valid-looking symbol that collides with someone else's product. For internal use such as asset tags, shelf labels or job sheets, Code 128 is the practical choice: it accepts letters and digits and is read by every general-purpose scanner.
Is the data I encode sent anywhere?
No. Both generators build the symbol in your browser and both scanners decode locally, so Wi-Fi passwords, UPI identifiers and contact details never leave your device. Nothing is logged, and the tools continue working with the network disconnected once the page has loaded.
Why won't my code scan even though it looks correct?
Work through the usual causes in order: quiet zone cropped too tight, insufficient contrast, printed too small for the reading distance, inverted colours, or a glossy surface throwing back a reflection. If the on-screen version scans and the print does not, it is almost always size or surface rather than the code itself.