Pinterest works like a search engine. When someone searches for "easy meal prep" or "small bathroom ideas", Pinterest looks at the words in your pin title, description, board name and alt text, along with the image, to decide whether your pin is a good match. A pin with a clear keyword in the right places has a better chance of being shown for that search.
This checker scores the text parts of a pin against one target keyword. It checks length, whether the keyword appears in each field, whether it appears early, whether the board name supports the topic and whether the link is valid. The score is a checklist, not a ranking prediction: it tells you whether the basics are in place so the image and the content can do the rest.
What the score checks
Title (30 points): a length that fits Pinterest's 100 character limit, the keyword present, and the keyword near the start. Description (35 points): a useful length, the keyword present and in the opening words, and no keyword stuffing. Board name (10 points): the board is named for the topic. Alt text (15 points): a real description of the image that mentions the topic. Link (10 points): a valid https address.
Matching is forgiving. If every word of the keyword appears but not as an exact phrase, the field gets partial credit. Check lengths in detail with the Pinterest character counter.
Write for people first
A pin that reads like a list of keywords tends to put people off, and saves and clicks are what keep a pin in circulation. Write the title as a promise ("15 Easy Fall Porch Ideas on a Budget"), then use the description to say what the reader gets and why it helps, using the keyword and one or two related phrases naturally.
If you are stuck for wording, the title generator, description generator and alt text generator give you drafts to edit.