Keyword tool APIs and bulk lookups: reading the small print on limits

The short version

Every keyword tool sells you a quota in its own unit, and where two vendors do use the same word they mean different things by it — so the plan that looks generous is often the one with the loosest definition. The only entry plan on this site that does not meter keyword research at all is SE Ranking's Core at $129 a month, which lists "Unlimited keyword, competitor and backlink research" among its features.

If you work in bulk or want to pull data programmatically, read the unit before the price. A hundred of one vendor's lookups can be worth a thousand of another's searches, or a tenth.

The six units, defined

• A lookup, in Mangools' sense, is one seed keyword expanded into a list. Basic allows 100 keyword lookups per 24 hours and returns up to 200 suggestions from each.
• A search, in Ubersuggest's sense, is one query in the interface. Individual allows 150 searches a day, with a separate cap of 50 keywords analysed at once.
• A credit, in Ahrefs' sense, is drawn down by many different reports across the product. Starter carries 200 credits a month, and Ahrefs states that additional credits cannot be purchased on that plan.
• A credit, in Keyword Insights' sense, is one clustered keyword. That is a different meaning of the same word on a different product.
• A report, in Semrush's free-account sense, is any report anywhere in the toolkit. The free plan allows 10 reports a day across all of them, shared.
• A keyword query, in Moz's sense, is one Keyword Explorer lookup. Standard allows 150 a month, which is five a day.

Why the comparison is not a league table

Those six definitions cannot be converted into one another. A Mangools lookup returning 200 suggestions and a Moz keyword query are not the same amount of work, and a Semrush report might be a keyword list or a backlink audit. Any chart that puts them on one axis — including the one on this page — is showing the shape of each vendor's generosity, not a ranking.

The honest use of that shape is to notice how differently vendors think about heavy users. Two tools cap you daily, one caps you monthly, one pools everything into a shared allowance, and one does not count at all.

What the entry plans allow for bulk work

Two entries there say "not published", and that is the answer rather than a gap in this research: if a vendor does not print it on the page where it prints everything else, this site does not estimate it.

Export limits are the ceiling people actually hit

For anyone whose work ends in a spreadsheet, the lookup counter is rarely the binding constraint. The binding constraint is how many rows a single export will give you, and that is a separate limit on most tools, often not printed on the pricing page at all.

Mangools publishes suggestion counts per lookup — 200 related keywords on Basic, unlimited on the higher plans — which is the closest thing to an export ceiling it states. Ubersuggest publishes a per-batch analysis limit of 50 keywords on Individual and 1,000 on Enterprise. Where a vendor does not publish an export cap, this site does not invent one, and it is a fair question to ask support before subscribing if bulk work is the reason you are buying.

Daily caps versus monthly caps

This is the difference that bites in practice. A daily cap cannot be banked: Mangools' 100 lookups reset on a rolling 24-hour basis, so a quiet fortnight buys you nothing for the afternoon you sit down to plan a whole site.

A monthly cap is the opposite trade. Moz's 150 keyword queries a month can all be spent on one Tuesday, which suits project work and punishes daily habits. Neither is better; they suit different working patterns, and choosing the wrong one is the most common reason people feel a tool is stingier than its price suggested.

What "unlimited" is worth

SE Ranking's Core plan is the only entry plan here that says unlimited about keyword research, and it prints no number at all — which is why the chart on this page leaves its bar open rather than inventing a height for it.

Unlimited in a software plan generally means no published counter rather than no ceiling, and fair-use provisions usually sit somewhere in the terms. The practical reading is that you are unlikely to hit a wall doing ordinary research, and that if your work is genuinely industrial, the API add-on with its stated 3M credits is the number to plan against rather than the word unlimited.

Before you pay for headroom

1. Count what you actually did last month. Most people who believe they need bulk access ran under fifty real lookups.
2. Check whether the cap you are hitting is on lookups or on rows returned. Increasing the wrong one changes nothing.
3. Look at export limits rather than lookup limits if your workflow ends in a spreadsheet, because that is where the real ceiling usually sits.
4. If you genuinely need bulk, price the unlimited plan against the next tier up of a metered one. SE Ranking's Core at $129 is often cheaper than a metered tool's top tier.
5. Treat an API as a separate purchase decision. It is rarely the reason to change tools, and on some plans it is explicitly capped or unavailable.

If none of this applies to you yet, it is a sign the cheap end of the market is still the right end. The eight keyword research tools with their entry prices covers that, and why the volume numbers you are pulling in bulk are estimates is worth reading before you build anything on top of them.