Score your first line 0–100 against a fully transparent checklist, then see your own words recast into three proven hook shapes. 100% in your browser.
On X, the first line isn't an introduction — it's a headline, an ad, and a filter rolled into one. A reader moving through the timeline gives each post something like a second of consideration. In that second, your opener either creates a reason to stop or it doesn't, and nothing below it gets a vote. This is why experienced writers spend a disproportionate amount of time on line one: a mediocre post with a sharp hook gets read and judged; a brilliant post with a limp hook gets scrolled past unjudged. The hook doesn't make the content good, but it decides whether the content gets its chance.
Every check in the analyzer maps to a mechanism, not a superstition. Numbers work because specificity signals evidence — "4,732 subscribers in 90 days" is a different epistemic object than "grew my newsletter fast." Brevity (under 12 words) works because a hook must be parseable in one visual fixation; a 30-word opener asks for commitment before offering a reason. Strong verbs and contrast words — stop, never, wrong, instead — create stakes and direction. Questions open a loop the reader wants closed. Personal stake("I", "my") converts advice into testimony, which is harder to dismiss. Concreteness checks penalize throat-clearing like "some thoughts on" — phrases that promise the reader work instead of payoff. And the hashtag check exists because hashtag piles read as spam to both humans and, by most practitioner accounts, the distribution algorithm.
The tool recasts your line into three shapes because most strong hooks on X are one of a small number of moves. Number-first suits lessons, lists, and results — it works when you genuinely have enumerable substance behind the line, and it fails (embarrassingly) when you don't. Question form suits posts whose payoff is an explanation; the question should be one your target reader has actually asked themselves, not a rhetorical setup. Contrarian flip is the highest-variance move: it buys attention with disagreement, so it only works when you hold the position for real and can defend it in the replies. Reflexive contrarianism reads as engagement bait within about two posts. The rewrites are mechanical transforms of your words — deliberately so. They show you the shape; you supply the judgment.
Heuristics are guardrails, not goals. The productive workflow is: write the line you mean, run it, and look at the failed checks as questions. No number — is there a specific figure you're leaving vague? Sixteen words — which six are decorative? No personal stake — did this happen to you, and if so, why hide it? Often the answer is "the line is right as it is," and you should ship it; a checklist can't see irony, timing, or the context of your audience. What the score reliably catches is the unforced errors — the hedged, abstract, throat-clearing openers that nobody defends on reflection but everybody writes on autopilot.
The fastest way to internalize all of this is volume on a single post: before publishing anything important, write ten different first lines for it. The first three will be obvious, the next four derivative, and somewhere in the last three you'll usually find the angle you actually believe. Score them, but pick with your gut — then check your pick against the post's performance. A few weeks of that loop and you won't need the analyzer for drafts; you'll need it only as a pre-publish sanity check, which is what it's for.
It's a weighted checklist, shown in full below your score: a specific number (+15), under 12 words (+15), a strong verb or contrast word (+15), a question (+10), a proven opener like I/How/Why/Stop (+10), personal stake (+10), concreteness (+10), no hashtag spam (+10), and no trailing ellipsis (+5). Every rule is visible — there's no model or black box behind it.
Absolutely. Heuristics measure whether your line uses patterns that usually work; they can't measure surprise, timing, or reputation — and some of the best hooks work precisely by breaking patterns. Treat a low score as a prompt to double-check the line, not a verdict. The reverse is also true: passing every check doesn't make a boring idea interesting.
Because on X the first line does the job a headline does elsewhere. In the timeline, readers decide in about a second whether to keep reading, expand, or scroll. For threads and long posts it's even more extreme: the opener is the only part most people ever see.
No. They're mechanical string transforms of your own line into three proven shapes — number-first, question form, and contrarian flip. That's deliberate: they keep your idea intact and show you the shape, so you edit from your own material instead of adopting someone else's canned line.
Specificity is credibility. 'I grew my newsletter' is a claim; 'I grew my newsletter to 4,732 subscribers in 90 days' is evidence with a built-in promise of a method. Numbers also set the scope of the payoff — '3 lessons' tells readers exactly what they're committing to.
No. The analysis runs entirely in your browser. Nothing you type is transmitted, stored, or logged.
DeckPost drafts in your voice, schedules at your peak windows, and reviews the numbers with you every week.