Try the demo

Check if a product sells before you buy stock.

SellProof searches Meta's Ad Library in each EU country you sell to and shows who already advertises your product, how many ads they run and for how long. The rule of thumb: when one competitor runs 100 or more ads, they're usually making money with it.

The demo is the same app with sample data. No account needed.

Product checkGermany, Poland, Netherlands, Spain
  • Real competitors found10
  • Most ads by one competitor251
  • Longest-running ad189 days
  • Shops selling it, with prices9
Worth testingSomeone already spends heavily to sell this.

Example results with sample data, the way SellProof shows them.

How SellProof decides

Brands rarely keep paying for ads that lose money. So the number of ads a brand runs, and how long it keeps them running, is a strong signal of what sells.

  1. Searches each country in its language

    Your words, the way buyers type them: “tragbarer Mixer” in Germany, “batidora portátil” in Spain. Not sure which words? It writes a prompt you paste into any AI chat.

  2. Keeps only ads about your product

    An ad must contain one of your words. AliExpress, Temu, Amazon and other marketplaces are left out.

  3. Counts every competitor's ads

    How many ads each brand runs in total, how many are about your product, and how long the oldest one has been live.

  4. Looks inside their shops

    For Shopify stores: the matching products, their prices and the crossed-out “was” prices.

  5. Gives you a verdict

    Worth testing when a competitor with 5 or more ads about your product runs 100 or more ads in total. Otherwise Maybe: look closer or Not proven. You can change both numbers.

Three tools in one app

Check a product

Pick a product, check the search words for each country and run the check. You get the verdict, the reason behind it and what to do next.

  • Competitors sorted by how many ads they run about your product
  • Their shops, prices and crossed-out prices
  • Save products and re-check them any time
SellProof product check: a green 'Worth testing' verdict, the reason, three key numbers and a table of competitors with their ad counts.
Product check (sample data)

Find winning ads

The ads that have run for weeks and reached the most people, per country. Look inside your product's niche or across every niche.

  • Hide big retailers like Lidl, Zalando and IKEA
  • See why each one made the list: days running, copies, people reached
  • Tick the ones you like and add them to your swipe file
Winning ads list for Germany: each ad with days running, number of copies, people reached and a link to the ad.
Winning ads (sample data)

Watch your competitors

Add brands by name. Each check compares with the last one: which ads are new, which stopped, and whether a brand is ramping up.

  • A long-running ad that stops gets flagged. It usually means they found something better.
  • A trend line per brand across your checks
Competitor watch: for each brand, the new ads since the last check and a warning for an ad that stopped after 93 days.
Competitor watch (sample data)

Your research stays on your computer

No SellProof account

SellProof runs on your computer and has no server of its own. Your settings, access token and reports are saved there.

Reports you can keep

Save any check as a web page, a table (CSV) or a Markdown note. The Reports tab finds them as you type, even with typos.

A swipe file that fits your notes

Winning ads go into one Markdown file, so they show up in Obsidian or any app that opens Markdown.

Before you buy

What SellProof needs and what it can't do, so there are no surprises.

EU and UK ads only
Meta's Ad Library API shows commercial ads for EU countries and the UK. Ads that only run in the US aren't included.
You need your own free Meta developer account
A one-time setup: confirm your identity at facebook.com/ID, create a free developer app and generate an access token. SellProof shows each step. You don't need to run any ads.
The access token lasts about 60 days
SellProof shows how many days are left. Then you make a new one the same way.
No spend or ROAS numbers
Meta doesn't publish them for product ads. SellProof works with what's public: how many ads run, how long, and how many people they reached.
Searches by keyword
The “must contain” words filter out most unrelated ads, but skim the results before you decide.
Runs on Windows, Mac and Linux
Windows 10 and 11, Macs with Apple Silicon (M1 or newer), and 64-bit Linux.

Get SellProof

€XX

[payment terms]

After payment you get the download link by email.

  • Check a product, Winning ads and Competitor watch
  • Reports as web page, CSV and Markdown
  • Swipe file in Markdown, ready for Obsidian
  • Installers for Windows, Mac (Apple Silicon) and Linux
  • Step-by-step help to connect your Meta account

Questions

Is this allowed by Meta?

SellProof uses Meta's official Ad Library API with your own developer account. It reads the same public ad data you can see at facebook.com/ads/library, country by country, without the clicking.

Does it work for the US?

No. Meta's Ad Library API shows commercial ads for EU countries and the UK only.

Do I need to run ads or have a business account?

No. You need a Facebook account to confirm your identity and create a free developer app. You don't need to run any ads.

What does the demo show?

The same app, with made-up brands, ads and shops. All three tools work, nothing is sent to Meta, and you don't need an account. Choosing where files are saved is only in the real app.

Can I change the rules for the verdict?

Yes. The number of ads a competitor must run, how many must be about your product and the minimum days for a winning ad are all in Settings.

Which computers does it run on?

Windows 10 and 11, Macs with Apple Silicon (M1 or newer), and 64-bit Linux.

Where is my data saved?

On your computer. SellProof sends your searches to Meta's Ad Library and reads competitors' public Shopify product lists. It has no server of its own.

Check your next product before you order it.