Check a manufacturer's nutrition page against the package you have
Match the market and variant, distinguish access dates from revision dates and preserve disagreements instead of choosing silently.
A manufacturer's product page can help investigate a label question, but first confirm that it describes your exact package. A matching brand logo is not enough. Market, flavor, pack size and preparation instructions all belong in the identity check.
Record the page before comparing
Save the page title, complete URL and date accessed. Copy any product code and explicit revision date if shown. Do not treat today's access date as evidence that the nutrition table was updated today. If the page supplies several variants, note which tab or selector was active.
For products offered online in the EU, the Commission explains the provision of relevant mandatory food information before purchase in its distance-selling guidance. That context makes the information useful to inspect; it does not guarantee that a particular page matches a particular package in your hand.
Compare the basis before the values
In a hypothetical example, your box lists 4 g fiber per 50 g, while the manufacturer's page lists 8 g per 100 g. These are numerically consistent after conversion: 4 ÷ 50 × 100 = 8 g per 100 g. Record the agreement with both original bases retained.
If the page instead lists 7 g per 100 g, save that as a discrepancy. Check for a different country selector, variant, serving preparation or package revision before proposing an explanation. Do not average the two values to produce a new number that neither source reports.
Use a focused evidence note
A helpful note has package value, page value, aligned basis, identity checks and unresolved question. Attach the package photograph and identify the specific page section. If the page changes later, a dated local reference helps explain what you observed, subject to your normal file and privacy practices.
When asking the manufacturer for clarification, provide the exact product and the conflicting fields rather than asking whether its website is correct in general. A clear question is whether the stated fiber amount applies to your market and pack version.
Update the working record only when the evidence supports an update. Preserve the previous value and reason for the change. If no clarification is available, state that the two sources disagree and identify which source you used for the particular package calculation. Do not turn an unresolved discrepancy into a claim of reformulation, deception or product danger.