Free 11+ papers are genuinely useful — but only if you use the answers to diagnose, not just to tick. The improvement comes from what you do after marking, not from downloading more PDFs.
A useful free paper comes with answers and, ideally, explanations. Sit it properly, then mark it together. For every mistake, ask: was it a topic your child doesn't understand, a careless slip, or running out of time? Those three need very different fixes.
Then act on the biggest pattern. If percentages keep coming up, a short free lesson on percentages will do more than another whole paper. Lean on free resources first, and only consider a paid resource once you know exactly what it's for.
What to do: use free papers to find gaps rather than collect scores, classify each mistake, fix the top gap with a free lesson, then re-test.
MindBlaze's free Learning Centre has lessons for the gaps a paper exposes, and Smart Papers turn the marked paper into a personalised list of exactly which ones to start with.