2,000 listings, 1 credit
Backlink checker sites versus an API for directories
If you run a tool directory, you need a link score for every listing, not one lookup at a time. Our own index of 181 million domains answers that over plain HTTP.
- Free: domain, overview, stats, suggest
- bulk_dr scores 2,000 domains per call
- $100 free credit, no card
$ curl "https://seotoolsai.org/api.php?action=bulk_dr&domains=ahrefs.com,moz.com,majestic.com&key=sk_live_..."
Checklist
Before you attach a link score to a listing
- Decide which listings deserve a score: all of them, or only the featured ones.
- Keep the score in its own column, with the date it was fetched next to it.
- Write down the formula, so a reader can see what the number means.
- Plan one refresh a month, because the index itself moves about monthly.
- Store the raw JSON once, then render pages from your own database.
- Never sort a paid placement above a better listing just because its score is higher.
Who it is for
Why backlink checker sites stop helping at 200 listings
Every directory owner starts the same way. You open one of the free backlink checker sites, paste a domain, copy the number into a spreadsheet and move on.
That works for twenty tools. It breaks at two hundred, because the copy-paste loop never ends, and the numbers go stale while you are still on row 140.
The fix is boring and cheap. Ask an API instead, for the whole column at once, and write the answer straight into the listing record. One bulk_dr call takes up to 2,000 domains and costs 1 credit, which is $0.0001.
Mind the label. Our ratings come from our own crawler and our own index, so they are our own metric. They are comparable in spirit to Ahrefs DR or Moz DA, but not the same number, and your page should say so. Honest labels keep readers, and they keep you out of arguments with vendors.
Start with the field reference for listings if you design the table first, or jump to the sync recipe if the spreadsheet already exists.
The index behind the score
- domains in our own link index
- 181,132,097
- domain-to-domain links
- 2,774,625,913
- backlinks indexed, refreshed roughly monthly
- 798.5 billion
- domains scored per bulk_dr call
- 2,000
- per 1,000 one-credit calls
- $0.10
- free credit at sign-up, no card
- $100
Curator's verdict
Fetch the number, keep the editorial judgement
A link score tells you how widely a site is referenced. It cannot tell you whether a tool is any good. Use the score to sort and to spot oddities, and let a human write the review.
- Good for: ordering large lists, flagging dead or thin listings, monthly refresh jobs.
- Weak for: keyword volumes, rank tracking, daily-fresh crawl. Ahrefs and Semrush are the fuller products there.
- Data is refreshed roughly once a month, so last week's new links may be missing.
One call for a whole category page
Replace the key with your own after sign-in. The free actions need none.
curl "https://seotoolsai.org/api.php?action=bulk_dr&domains=ahrefs.com,moz.com,majestic.com,semrush.com&key=sk_live_..."
# free, no key: one domain at a glance
curl "https://seotoolsai.org/api.php?action=overview&q=moz.com"Compare
A single-lookup checker against an API you can loop
| Point | Web checker form | API call from your sync job |
|---|---|---|
| Domains per request | One | Up to 2,000 with bulk_dr |
| Cost model | Free with limits, or a seat on a plan | Prepaid credit, $0.0001 per call |
| Output | A page to read | JSON for your database |
| Refresh | Whenever you remember | A monthly cron or n8n schedule |
| Best for | A quick look at one tool | A column of scores for every listing |
FAQ
Questions directory owners type
What are the best backlink checker sites for a tool directory?
For a few listings, any free web form will do. Past a few hundred, forms become a chore, so use an API. Ours scores up to 2,000 domains in one call for 1 credit, and domain, overview, stats and suggest are free without a key.
Can I show a free backlinks checker tool on my own site?
Yes. The free domain action needs no key and CORS is open, so a browser widget can call it directly. Heavier actions need a key, and a key in front-end code is visible to every visitor, so keep those on your server.
How often should I refresh the scores in my listings?
Once a month is enough. Our index refreshes about monthly, so running the job more often returns the same numbers and burns credit for nothing. Date-stamp each score so readers can see how old it is.
Is this DR the same as Ahrefs DR or Moz DA?
No. It is our own 0-100 metric, round(100 log(ref_domains + 1) / log(2 10^7)). It behaves in a similar spirit but the numbers will differ, so label it with our brand when you show it.
What does it cost to score 5,000 listings every month?
Three bulk_dr calls cover 5,000 domains, which is 3 credits or $0.0003. The $100 free credit is 1,000,000 credits, so the scoring itself is nearly free. Detail calls such as refdomains cost 2 credits each.
Do I need a subscription or a card?
No. Sign in with Google and the $100 credit is added without a card. Later top-ups are USDT (TRC-20) from the account page, and nothing recurs unless you top up again.
Can I load the scores into Google Sheets or n8n?
Yes, with a plain HTTP request. The sync recipe shows a Python version and describes the same call in a spreadsheet or n8n workflow, including what to do on a 402.