Runway sells a suite rather than a single generator: text to video sits alongside inpainting, motion controls and a timeline editor. That breadth is also why the credit maths matters more here than on a simpler tool: one grant has to cover several different kinds of work.
What the free plan actually buys you
The free plan grants 125 credits once, not 125 credits a month. That is the single most important line on the pricing page and the easiest to misread. Synthesia, Descript and HeyGen all refill monthly, and Pika's pricing page now lists its free tier at zero monthly credits with packs only; this one does not refill either. Once those credits are spent, the account keeps working but cannot generate.
The entry price is the struck-through one, not the one in the title
This profile carried no entry price for a while, because the Standard card prints two monthly figures side by side and an earlier reading could not tell which applied month to month. The card answers it now: $15 is shown struck through beside $12, under the line billed annually, save $36 per year. Three dollars a month across twelve months is thirty six, so the two figures and the saving agree with each other.
The number at the top of this profile is $15, and that is deliberately not the number Runway leads with. Its own pricing page is titled from $12 a month, which is the rate for committing to a year. If you want to be able to stop after a month, $15 is what you pay.
AI video is the hub for this category, and the Runway review reads the same figures against the terms. Runway vs Pika is the head to head this category needs first, because the two credit systems answer the same questions differently.