Comparison
BigSpy is the affordable all-rounder — a big multi-platform ad library that won't wreck your budget. It's great for casting a wide net. It can't tell you which ad in that net is worth keeping.
BigSpy aggregates ads from Facebook, Instagram, TikTok, YouTube, and more into one searchable library at a lower price point than the premium databases.
If your job is finding what's live, BigSpy does it. Keep it.
BigSpy will show you the most-liked ads in your niche across four platforms. BigSpy, like every ad spy tool, is a database: it shows you an ad exists and, at best, how long it's run. It cannot tell you whether the creative actually holds a viewer's attention — which is the only thing that decides whether an ad is worth copying. That's not a knock on BigSpy; no database can see inside the creative. It's a different layer.
BigSpy is the card catalog — every ad indexed, none of them read. PreTestAds is the librarian who read them all. Point an AI agent with the PreTestAds MCP at any advertiser and it scores each live ad for predicted attention, then hands back a verdict on every one:
The verdict a spy database can't give you
HIDDEN GEM
Great creative nobody's backing — steal it early
MODEL IT
Proven winner — copy the structure
SKIP
Nothing to learn or beat
OUT-HOOK IT
They're committed to weak creative — beat it
Creative attention score →
Run time fools everyone — a long-running ad looks like a winner and is often just coasting on autopilot budget. A score doesn't guess (more in how to tell if a competitor ad is working).
Use BigSpy to cast the wide, cheap net, then score the ads that catch your eye so engagement counts don't trick you into copying a dud. See it in practice on 7 real competitor ads we pulled and scored, or read the honest landscape in best Facebook ad spy tools.
Score any competitor ad for attention before you model it. First analysis free.
Score an AdThey solve different problems. BigSpy is a budget-friendly database of live ads across Facebook, Instagram, TikTok, and more; PreTestAds scores whether a given ad's creative holds attention. Use BigSpy to find ads, PreTestAds to judge which are worth copying.
No. BigSpy sorts by likes, shares, and run time — signals that an ad got seen, not that the creative works. It can't read whether the ad holds a viewer's attention, which is what actually predicts performance.
The judgment BigSpy lacks. Score any ad you found in BigSpy for predicted attention and get a model / out-hook / hidden gem / skip verdict, so a cheap database becomes a shortlist of ads actually worth modeling.