Validating a batch of QR destinations before anything goes to print
A single wrong URL is a typo. A hundred wrong URLs is a print run in the bin. Batch validation exists for the moment when a list of destinations leaves a spreadsheet and heads for a printer: dozens or hundreds of codes, each one a promise to a scanner. Checking them one at a time is slow and unreliable, and skipping the check means the first person to find a mistake is a customer. The discipline is simple — validate the whole list, fix every failure, review every warning, and only then generate the codes.
The failures this tool catches are the quiet ones. A missing scheme turns a URL into plain text that no scanner will open. Whitespace copied from a spreadsheet cell breaks the link invisibly. Credentials embedded in a URL — user:pass@host — leak secrets into every printed copy. Duplicates are the most wasteful failure of all: two codes, two labels, two tracking entries, all pointing at the same page, because the list was merged from two sources and nobody noticed. Catching duplicates case-insensitively matters, since hosts ignore case and trailing slashes rarely change the destination.
Warnings deserve attention even though they are not failures. Plain HTTP destinations work, but they train visitors to accept unencrypted pages and they fail the trust test for anything involving a form or payment. Very long URLs work too, but they encode as dense symbols that need larger print and better cameras. Both are fixable upstream: serve the page over HTTPS, and point the code at a short redirect you control rather than a URL with a long query string. Fixing the destination is almost always cheaper than compensating with print size.
Know what batch validation does not cover. It checks format, not reachability: a perfectly formatted URL can still point at a page that returns an error, a campaign that ended, or a redirect that now leads elsewhere. Pair format validation with a reachability check from your own monitoring or a terminal request, and with a human glance at the destinations themselves. A list that passes format validation and points at last year's campaign is still a failure — just a well-formatted one.
Finally, treat the validated list as the single source of truth. Generate the codes from it, keep it with the job file, and re-validate it whenever it changes. A list that lives in a spreadsheet, gets edited by three people, and is pasted into a generator from memory will drift. A list that is validated, exported, and versioned will not. The cost is minutes; the saving is a reprint.