Call-to-action strength checker
The sample trial sign-up phrase scores 93 of 100: 40 of 40 for opening with the verb “start”, 35 of 35 for clarity and 18 of 25 for the cue “today”. Plain reasons show which words to revise before a design review. Free in your browser.
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Worked example
- Text
- Start your free trial today
- Phrase
- Start your free trial today
- Score
- 93
- Rating
- very_strong
A strong call to action tells the reader what to do, makes the next step easy to understand, and, when appropriate, gives a reason to act promptly. This checker evaluates a single CTA phrase against those three qualities and returns a score from 0 to 100. It also breaks the result into action verb, urgency, and clarity components, so you can see exactly why a phrase earned its score and decide which words deserve revision.
What the score measures
The checker uses a fixed 100-point rubric rather than a language model or a subjective impression. Action language contributes up to 40 points because a CTA should name the behavior it asks the reader to perform. A recognized verb earns the most credit when it opens the phrase, where it is easiest to notice.
Urgency contributes up to 25 points when the phrase includes language such as “now,” “today,” or a limited-time cue. Clarity contributes the remaining 35 points. That component rewards a concise, scannable length, an explicit action, and enough meaningful context to indicate an outcome or destination.
The response includes every component, its maximum, and plain-English reasons. This makes the score useful as a consistent editing signal: two writers can compare alternatives under the same rules instead of debating an unexplained number. It does not predict conversions, judge visual design, or claim that urgency belongs in every message.
How to improve a weak call to action
Start with the component that lost the most points. If action language is missing, rewrite the phrase around a direct verb that matches the real next step: “Download the guide,” “Book a consultation,” or “Compare plans” is clearer than a passive label such as “More information.” If clarity is low, remove setup words and keep the phrase focused on one action.
Then add just enough context to identify what happens after the click. A bare “Get” is short but vague, while “Get the pricing guide” gives the reader a concrete expectation. Treat urgency carefully.
Add “today,” “now,” or a genuine deadline only when prompt action matters and the claim is true. Artificial scarcity can raise this mechanical score while damaging trust. The best revision therefore improves specificity first, preserves the brand’s voice, and uses urgency only when the offer, availability, or customer need honestly supports it.
Compare variants without mistaking the score for a forecast
Use the checker to screen and compare CTA variants before they enter a design review or experiment. Keep the surrounding offer constant, submit each phrase separately, and inspect both the total and the reasons. A higher result means the wording more clearly exhibits the rubric’s action, urgency, and clarity signals; it does not guarantee a higher click-through or purchase rate.
Context still matters. “Learn more” may be appropriate for an early educational step even though it is less specific than “Download the security checklist.” Likewise, a checkout button rarely needs a countdown phrase because the page itself supplies context and intent.
After selecting promising variants, test them with real users or controlled traffic and evaluate downstream quality, not clicks alone. The algorithm is deterministic, so the same normalized phrase always produces the same result. That consistency makes it suitable for editorial checklists, content pipelines, and repeatable QA while leaving the final persuasion decision with the team.
What you can do with it
Review landing-page buttons
Check whether a hero or pricing-page button states a clear action and outcome before the page reaches design review.
Compare campaign variants
Score several CTA phrases under one transparent rubric, then send the strongest appropriate options into an A/B test.
Add consistency to content QA
Flag passive, vague, or overly long calls to action in a repeatable editorial workflow without relying on a subjective first impression.
FAQ
What does the score include?
The 0–100 score combines action verb presence and placement, urgency language, and clarity based on length, explicit action, and useful context.
Does a higher score guarantee more conversions?
No. The score measures wording signals under a fixed rubric. Audience, offer, placement, design, and trust can matter more, so validate important choices with real testing.
Does every CTA need urgency language?
No. Urgency can strengthen time-sensitive offers, but it should be truthful and appropriate. A clear non-urgent CTA may be better for educational or considered decisions.
Is the analysis deterministic?
Yes. It uses fixed word lists and rules with no network, model, randomness, or current-time dependency, so the same phrase produces the same result.
How do I improve a low call-to-action score?
Start with the part that lost the most points. Open with a direct verb for the real next step, such as “Download the guide”, and add enough context to show what happens next: “Get the pricing guide” beats a bare “Get”.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/write/cta-strength-check \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"text":"Start your free trial today"}'const res = await fetch("https://api.kit.forhosting.com/write/cta-strength-check", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"text": "Start your free trial today"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/write/cta-strength-check",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"text": "Start your free trial today"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/write/cta-strength-check", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"text":"Start your free trial today"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"text":"Start your free trial today"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/write/cta-strength-check", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"text": "Start your free trial today"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "write.cta_strength_check",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Limits
max_tokens | 20000 |
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical questions
What happens if the phrase is empty?
An empty or whitespace-only phrase returns an invalid_input error because there is no call to action to evaluate.
What does it cost through the API?
Each request costs $0.002. The same deterministic analysis can also run in the browser.