A QR code is just data printed as pixels — it cannot expire. What can stop working is the destination behind it: a dynamic QR code points at a redirect service that might shut down, and a plain link dies if the target page does. Codes you generate locally with plain content keep working forever.

Are QR codes safe to scan?

The code itself is inert; the risk is where a URL points. Attackers print codes that lead to phishing sites, so treat a decoded link like any unknown link — read it before opening. Using a scanner that shows you the destination first, instead of jumping straight to the browser, is the safe habit.

What is the difference between static and dynamic QR codes?

A static code encodes the final content directly — a URL, Wi-Fi credentials, text — and works forever. A dynamic code encodes a short redirect URL owned by the service that made it, letting the destination be changed later; it works only as long as that service exists, and it tracks every scan.

How much data can a QR code hold?

Up to about 4,300 characters in the largest version at the lowest error-correction level. The practical limit is much lower: every extra character adds modules, making the code denser and harder to scan — keep payloads short, especially for print.

QR Code yog dab tsi?

Cov dub-thiab-dawb square puzzles ntawm cov ntawv qhia zaub mov, cov ntawv tshaj tawm thiab cov ntawv hla tebchaws tuaj yeem ntim cov ntawv txuas, Wi-Fi daim ntawv pov thawj lossis daim pib mus rau ob peb square centimeters. Nov yog qhov lawv ua haujlwm li cas - thiab yuav ua li cas los tsim thiab luam theej duab lawv yam tsis tau ntes tau.

Pixels raws li cov ntaub ntawv

QR code — Quick teb chaws, tsim nyob rau hauv 1994 los ntawm Denso Wave rau kev taug qab cov tsheb qhov chaw - yog ib tug ob-dimensional barcode. Qhov twg lub khw muag khoom qub barcode khaws cov lej kaum hauv ib qhov ntev, QR code khaws cov ntaub ntawv hauv ob qhov ntev: ib daim phiaj ntawm dub thiab dawb modules, txhua tus me ntsis. Yog vim li cas QR code tuaj yeem tuav ntau txhiab tus cim tsis yog kaum tus lej.

Cov ntaub ntawv tuaj yeem yog txhua yam bytes tuaj yeem sawv cev: ib qho URL, cov ntawv dawb, cov ntaub ntawv tiv tauj, Wi-Fi daim ntawv pov thawj, txawm tias cov ntaub ntawv binary hauv txoj kev xav. Lub scanner nyeem daim phiaj, rov tsim cov bytes, thiab txhais lawv.

Anatomy ntawm QR code

Peb qhov chaw pom kev pom ua rau QR code txiav tawm tau los ntawm txhua lub kaum sab xis:

Element	Qhov twg	Lub luag haujlwm
Finder qauv	Peb lub kaum loj squares	Cia lub scanner nrhiav tus lej thiab nws txoj kev taw qhia
Cov qauv sib txawv	Me me square, hauv qab-txoj cai cheeb tsam	Kho rau lens distortion ntawm qhov chaw nkhaus
Sijhawm qauv	Alternating kab ntawm finders	Teem lub module grid coordinates
Nyob ntsiag to	Dawb margin tag nrho ib ncig	Cais cov cai los ntawm nws ib puag ncig - ib feem ntawm tus qauv, tsis txhob cog qoob loo
Cov ntaub ntawv & kev kho qhov yuam kev	Lwm yam	Lub payload, interleaved nrog redundancy

Muaj 40 "versions" - qhov ntau thiab tsawg ntawm 21 × 21 txog 177 × 177 modules. Cov ntawv loj dua tuav cov ntaub ntawv ntau dua; ib txwm URL tsaws nyob ib ncig ntawm version 3-5.

Vim li cas cov lej puas tseem scan

QR code embed Reed-Solomon yuam kev kho - tib yam lej uas tiv thaiv CDs thiab qhov chaw sib sib zog nqus. Txog rau ib feem ntawm cov modules puas, tus decoder reconstructs cov ntaub ntawv uas ploj lawm es tsis txhob ua tsis tau tejyam. Plaub theem kev lag luam muaj peev xwm rau resilience:

L - rov qab ~ 7% kev puas tsuaj; densest code.
M - 15%; lub neej txhua hnub.
Q - 25%; zoo rau kev luam ntawv uas yuav ua haujlwm.
H - 30%; cia koj nplawm lub logo hauv nruab nrab, muaj sia nyob ntawm qhov chaw ntxhib.

Qhov no kuj yog vim li cas cov lis dej num zam lub logo overlay: tsuav yog kev puas tsuaj nyob qis dua cov peev nyiaj rov qab, cov nyiaj them poob qis.

Static vs dynamic codes

A zoo li qub QR code encodes cov ntsiab lus kawg ncaj qha. Nws ua haujlwm tas mus li, tsis muaj nqi, taug qab tsis muaj dab tsi - hloov lub hom phiaj thiab koj rov luam tus lej. A dynamic code encodes luv luv redirect URL uas muaj los ntawm ib tug QR kev pab cuam: cov kev pab cuam log txhua scan thiab yuav repoint lub lo lus uas peb tom qab. Yooj yim rau kev tshaj tawm, tab sis nws ntxiv qhov kev vam khom (qhov kev pabcuam yuav tsum nyob twj ywm), taug qab kev ceev ntiag tug, thiab feem ntau yog kev tso npe. Peb QR generator tsuas yog tsim cov lej zoo li qub - tsis muaj dab tsi tas sijhawm, tsis muaj xov tooj hauv tsev.

Dab tsi cov neeg muab tso rau hauv

URLs - cov ntawv tshaj tawm, daim npav lag luam, ntim khoom.
Wi-nkaus — cov WIFI:S:name;T:WPA;P:password;; hom ntawv koom nrog lub network ntawm scan; peb lub tshuab hluav taws xob tsim nws rau koj.
vCards - daim npav tiv tauj hauv ib qho scan.
Email, xov tooj, SMS - ua ntej sau cov ntawv sau.
Kev them nyiaj thiab daim pib - Kev kos npe ib zaug, yog vim li cas cov lej no yuav tsum tsis txhob rov siv dua lossis thaij duab los ntawm cov neeg txawv tebchaws.

Scanning yam xyuam xim (quishing)

Vim tias tus lej tsuas yog qhov txuas ib tus neeg luam tawm, cov neeg tawm tsam siv lawv ib yam nkaus - cov txheej txheem txawm muaj lub npe, quishing (QR phishing). Cov ntawv nplaum tau nplawm dhau cov lej raug cai ntawm cov chaw nres tsheb, cov lej hauv email uas ua rau cov nplooj ntawv sau ntawv pov thawj: lub xov tooj qhib qhov chaw tsis pom, thiab qhov ntawd yog qhov txaus ntshai.

Siv lub scanner uas qhia cov ntsiab lus decoded ua ntej qhib — zoo li QR scanner ntawm qhov chaw no - tsis yog ib qho uas dhia ncaj nraim mus rau qhov browser.
Nyeem qhov sau kom zoo: paypa1.com tsis yog PayPal.
Ua kom tsis txhob xav txog cov lej uas tuaj txog npog lwm cov lis dej num, lossis qhov xav tau nkag mus tam sim tom qab luam theej duab.

Tau txais QR code ua duab? Txiav txim siab nws tsis ntseeg nws: lub QR nyeem ntawv qhia cov ntsiab lus nyoos ntawm ib daim duab, hauv zos, ua ntej koj qhib dab tsi.

Kawm ntxiv

Tsim ib: lub QR code generator (txuas, Wi-Fi, email, SMS — PNG download).
Read one live: tus QR scanner nrog koj lub koob yees duab, los yog lub nyeem ntawv rau cov duab.
Xav paub txog qhov chaw nyob hauv QR txuas? Pib nrog qhov chaw nyob IP yog dab tsi.

FAQ

QR cov lus nug

QR cov lej puas tas sijhawm?

QR code tsuas yog cov ntaub ntawv luam tawm raws li pixels - nws tsis tuaj yeem tas sijhawm. Dab tsi tuaj yeem tso tseg tsis ua haujlwm yog qhov chaw nyob tom qab nws: lub zog QR code cov ntsiab lus ntawm kev xa rov qab cov kev pabcuam uas yuav raug kaw, thiab qhov sib txuas dawb tuag yog tias nplooj ntawv lub hom phiaj ua. Cov lej koj tsim hauv zos nrog cov ntsiab lus yooj yim ua haujlwm mus ib txhis.

Puas yog QR cov lej muaj kev nyab xeeb los luam theej duab?

Txoj cai nws tus kheej yog inert; qhov kev pheej hmoo yog qhov twg URL cov ntsiab lus. Cov neeg tawm tsam luam tawm cov lej uas ua rau phishing qhov chaw, yog li kho qhov txuas txiav tawm zoo li ib qho txuas tsis paub - nyeem nws ua ntej qhib. Siv lub scanner uas qhia koj qhov chaw ua ntej, es tsis txhob dhia ncaj nraim mus rau qhov browser, yog tus cwj pwm nyab xeeb.

Dab tsi yog qhov txawv ntawm cov lej zoo li qub thiab dynamic QR code?

Tus lej zoo li qub encodes cov ntsiab lus kawg ncaj qha - URL, Wi-Fi daim ntawv pov thawj, ntawv nyeem - thiab ua haujlwm tas mus li. Ib tug dynamic code encodes luv luv redirect URL muaj los ntawm cov kev pab cuam uas ua rau nws, cia cov lo lus uas peb yuav hloov tom qab; nws ua haujlwm tsuas yog ntev npaum li qhov kev pabcuam ntawd muaj, thiab nws taug qab txhua qhov scan.

QR code tuav tau npaum li cas cov ntaub ntawv?

Txog li ntawm 4,300 tus cim hauv qhov loj tshaj plaws ntawm qhov qis tshaj qhov yuam kev-kho. Qhov kev txwv qhov ua tau qis dua: txhua tus cim ntxiv ntxiv cov qauv, ua rau cov lej denser thiab nyuaj rau kev luam theej duab - khaws cov nyiaj them luv luv, tshwj xeeb tshaj yog rau luam tawm.