Your link breaks when lowercased: what to preserve

Visible text can hide a different address

You prepare a message containing an event programme. The original link opens the document, but the published version fails despite looking the same. Before uploading the file again, copy the published link’s address and compare it with the original. Reading the letters displayed on screen is not enough: an editor can show one label while associating it with a different address. The problem may be in that saved destination rather than in the file itself.

The questions consulted document uncertainty about URL capitalization and cases where visible text retained its spelling while the destination became lowercase. They establish a real need, not a claim that every platform currently has this defect. This guide uses a public programme and WikiURL tools to locate differences. It does not assume that every changed letter causes an error or that the checker can automatically fix the configuration of another website on your behalf.

Hostnames and paths do not follow the same rule

RFC 3986 states that schemes and hostnames are case insensitive; other components are assumed case sensitive unless specific rules say otherwise. Converting the host EXAMPLE.invalid to example.invalid therefore differs from changing Guias to guias or AB12 to ab12. Both examples use a fictional domain that does not work. Replace it with a real authorized destination before any connection test; here the addresses only serve to compare text and distinguish which components have changed.

The server decides how to resolve its paths and interpret its application parameters. Some sites redirect variants, while others may return different resources or errors. Do not infer that a path accepts lowercase merely because the hostname does. Google Search also explains that it treats paths such as /APPLE and /apple as distinct URLs. This informs consistency on a site you manage, but does not let you freely rename links supplied by an external provider.

https://EXAMPLE.invalid/Guias/PlanA.pdf?edicion=AB12
https://example.invalid/guias/plana.pdf?edicion=ab12

Compare components before transforming anything

In the JavaScript example, URL separates the hostname, path and query. MDN describes pathname as the path component and notes that query parameters are not part of it. Running the example only parses a string; it does not connect to the fictional site. Notice that the hostname is normalized while Guias, PlanA and AB12 retain their spelling. This separation helps identify precisely what changed between two copies, without confusing the domain with the resource’s actual identifier.

Avoid applying toLowerCase to the complete address as a cleaning operation. If an identifier belongs to another application, you do not know whether its mixture of letters matters. Preserve its parameter names and values as supplied by the issuer too. If choosing your own labels for a new campaign, agree their spelling when creating them; that is different from retrospectively transforming a link already identifying a resource. Keep an original copy so that you can compare changes later.

const u = new URL("https://EXAMPLE.invalid/Guias/PlanA.pdf?edicion=AB12");
console.log(u.hostname); // example.invalid
console.log(u.pathname); // /Guias/PlanA.pdf
console.log(u.search);   // ?edicion=AB12

Check each public version with WikiURL

For a public address without secrets, use WikiURL’s URL checker and inspect the HTTP status and detected final destination. If an original and an altered copy need comparison, check each separately. Do not submit private management links, tokens or confidential addresses. Restrict the test to the specific variants you already have, without enumerating identifiers or looking for other people’s resources. A difference in responses can help locate where the problem starts rather than proving its cause by itself.

If the original works and the lowercase copy returns an error, restore the original spelling before distribution. Do not attribute every 404 exclusively to capitalization: a resource might have been removed or its path copied incorrectly. If both responses are 200, open the pages and confirm the programme, date and contents. Status alone does not demonstrate equivalence. Inspect a redirect through the detected destination and then in the reader’s browser, checking the actual resource rather than only the status number.

Edit the button destination rather than only its label

Open the edit-link option in the tool used to compose the message. Examine the address field rather than just the button text. In HTML, the example separates href from the word PDF. The address is fictional and must be replaced before use. You can present a short or uppercase label without changing the letters in the real address. What matters is that the saved destination matches the approved one, regardless of how the surrounding design displays its label.

After saving or publishing, copy the final link’s address again and open it in the context your audience will use. For an exported document, inspect the exported file; for a message, inspect the received message. Content in the editor before sending does not establish what was actually published. If an unexpected transformation appears, correct the relevant field or consult that platform’s administrator, keeping both versions as evidence of the observed change. Test the correction in the final distributed version.

<a href="https://example.invalid/Guias/PlanA.pdf?edicion=AB12">PDF</a>

Shorten or make the QR from the checked address

Once the destination is correct, paste it exactly into WikiURL to create the short link or QR you intend to share. Preserve the spelling returned by the tool and test the final result too. Do not uppercase an entire URL for design reasons or assume that every short code tolerates letter changes. A QR represents the text it contains; it cannot guess which version of a path the author meant to offer when preparing the material.

If you control the website and need an address that is easy to dictate, request a stable path or deliberate redirect and test it. Merely writing a prettier version does not make that destination exist. Record the approved address, its placements and what was checked before printing or sending. The practical rule is simple: a label can adapt to the design; preserve the address until the resource administrator confirms an alternative that actually works for the intended audience.