User Guide
Fill both lists
Put one set of words in the first box and another in the second, one per line. Ten words against ten gives a hundred pairings, which is about the largest list worth reading by eye — so keep each side short and deliberate rather than exhaustive.
Choose the separator
Four options. None welds words together for brand names. Hyphen produces the readable form domains and URL slugs prefer. Underscore suits file names, database keys and code identifiers. Space gives ordinary two-word phrases.
Set the capitalisation
lowercase for domains and slugs. UPPERCASE for constants and headings. Capitalise Each for names as they would be written on a sign. camelCase for variable names, joining the second word with a capital and no gap.
Decide the order
A + B keeps your first list leading. B + A reverses it. Both ways returns each pairing in both directions and doubles the output — worth it when you genuinely do not know which reads better, since “skyfall” and “fallsky” are not equally good.
Filter to real words if you want
All combinations returns everything. Real words only keeps just those pairings that are themselves dictionary words — a much shorter list, and the right setting when you are hunting for a genuine compound rather than inventing one.
About the Word Combiner
Two lists in, every pairing out, formatted the way you need it. The job is mechanical, which is precisely why doing it by hand goes wrong.
The arithmetic people underestimate
Combining lists produces a Cartesian product: every item on the left paired with every item on the right. Ten against ten is a hundred results; twelve against twelve is 144; twenty against twenty is four hundred, and doubles again to eight hundred if you ask for both orderings. Attempting that on paper guarantees omissions, and the ones you miss are not random — people skip the combinations that feel awkward, which are sometimes the interesting ones.
What each formatting option is actually for
The separator, case and order settings exist because the output usually has a destination with rules. Hyphen and lowercase produce valid domain labels and URL slugs. Underscore suits database columns and file names. camelCase matches the variable naming convention used across JavaScript and Java. Capitalise Each is how a name appears on a sign. Choosing correctly at this stage saves reformatting several hundred rows later.
Why order matters more than it looks
Both ways doubles your output for a reason: compounds are not commutative in English. Skyfall and fallsky contain identical parts and only one is a name. If you cannot predict which direction will read better — and usually you cannot — generating both and judging by eye is faster than reasoning about it.
The real-words filter, and what it actually tells you
Switched on, each combination is looked up in the dictionary and only existing English compounds survive. That turns the tool from an invention machine into a discovery one. Read the result carefully, though: for branding, a combination that is already a word is harder to secure, not easier. Existing words are more likely to be registered as trademarks and their domains are almost certainly taken. The filter tells you what exists, never what is available.
Where it runs
In your browser, against a local dictionary. A list of unannounced product names never leaves your machine, which matters more here than on most tools.
Frequently Asked Questions
How many combinations will I get?
The two list lengths multiplied, and doubled again if you choose Both ways. Ten and ten gives 100, or 200 both ways. Lists of a few dozen each produce output too long to read usefully.
What does camelCase do exactly?
It lowercases the first word and capitalises the start of the second with no separator, giving forms like skyFall. It is the standard naming convention for variables in JavaScript, Java and several other languages.
Does Real words only mean the result is available as a domain?
No, and usually the opposite. A combination that is already an English word is far more likely to be registered. The filter tells you what exists, not what you can have.
Can I combine three lists?
Not in one pass. Combine the first two, paste the output into one side, and run it again with the third list. Be aware the count multiplies quickly.
Does it keep my word order within each list?
Yes. Output follows the order of the first list, with each of its words paired against the second list in turn, so results are predictable rather than shuffled.
Is there a limit on list length?
No hard cap, but readability collapses well before any technical limit. Keep each side under about twenty words unless you plan to filter the output elsewhere.