Time-to-First-Action: Why 1.8 Seconds Is the Perfect Time to Start Interaction

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Analysis of the distribution of time to first click as a signal of human presence

Introduction: The Silence That Says It All​

You visit a website. The page loads. You wait. After 1.8 seconds, you hover over the "Email" field.

This pause isn't empty. It's the first trust signal that fraud engines (Forter, Sift, Riskified) use to determine: "Is this a human or a bot?"

Because real people don't click instantly. They look, they read, they think. Their first action is the result of cognitive processing, not an automatic reaction.

In this article, we'll explore why 1.8 seconds is the sweet spot, how to simulate natural latency, and how to avoid the trap of "instant" behavior.

Part 1: What is Time-to-First-Action (TTFA)?​

Technical definition​

Time-to-First-Action (TTFA) is the time between a page fully loading and the first user interaction (click, scroll, input).

This metric is one of the earliest and most powerful signals in behavioral analysis.

Key insight:
TTFA is a window into the user's cognitive process.

Part 2: Statistics of Real Behavior (2026)​

TTFA distribution among real users​

Range	Share of users	Interpretation
< 0.5 sec	3%	Automation / bot
0.5–1.0 sec	12%	Very quick decision making
1.0–2.0 sec	68%	Norm (golden mean)
2.0–3.5 sec	15%	Slow reading / doubt
> 3.5 sec	2%	Distraction/technical problems

Median TTFA: 1.8 seconds - that's why this value is considered ideal.

Part 3: Why TTFA is so important for fraud engines​

Three levels of analysis​

Level 1: Reaction Speed

• Bots: TTFA = 0.1–0.3 sec (instant reaction),
• People: TTFA = 1.0–2.5 sec (information processing time).

Level 2: Contextual Consistency

• If TTFA = 0.2 sec, but the page contains complex conditions → anomaly,
• If TTFA = 2.5 sec for a simple landing page → it’s also an anomaly.

Level 3: Correlation with other metrics

• TTFA correlates with:
  • Session depth,
  • The number of errors,
  • Return frequency.

Example:
TTFA = 0.3 sec + perfect input + no scrolling → fraud score = 95+

Part 4: How to Model a Plausible TTFA​

Rules of natural delay​

1. Consider the complexity of the page

• Simple landing page (1 button) — TTFA = 1.2–1.8 sec,
• Complex form (many fields)— TTFA = 1.8–2.5 sec,
• Terms and Conditions Page - TTFA = 2.0–3.0 sec.

2. Add micro-oscillations

• Don't use a fixed delay,
• Vary TTFA within ±0.3 sec from the median.

3. Link to pre-scroll

• Before the first click, scroll down and back slightly,
• This simulates reading headlines.

Example:

• Page loading,
• Scroll down 200 px (0.5 sec),
• Return to top (0.3 sec),
• Pause 1.0 sec,
• First click → TTFA = 1.8 sec.

Part 5: Setting Up Dolphin Anty / Linken Sphere​

Human Emulation Settings​

Parameter	Recommended value	Why
Time-to-First-Action	1.5–2.0 sec	Corresponds to the median of real users
Pre-Action Scroll	Turn on	Simulates reading
Randomization	±0.3 sec	Adds variability
Context Awareness	Turn on	Increases TTFA for complex pages

Pro Tip:
Use "Natural First Action Delay" in Dolphin Anty - it automatically adapts TTFA to the page content.

Part 6: Why Most Carders Fail​

Common Mistakes​

Error	Consequence
Instant click (<0.5 sec)	Looks like a bot → high-risk score
Fixed delay	Lack of variability → suspicion
Ignoring context	TTFA does not match page complexity → anomaly

Field data (2026):
Profiles with TTFA <0.5 sec have 4.5 times higher fraud score, even with ideal IP and device.

Part 7: A Practical Example – Purchasing on Steam​

Step 1: Loading the Page​

• The Add Funds page has loaded.

Step 2: Preliminary Interaction​

• Scroll down to "Terms of Service" (0.6 sec),
• Return to the amount (0.4 sec).

Step 3: Pause​

• Reading conditions (1.0 sec).

Step 4: First Action​

• Click on the "Email" field → TTFA = 2.0 sec.

Result:
The fraud engine sees: “This is a person who reads the terms and conditions” → trust is increased.

Conclusion: A pause is the breath of the mind​

Time-to-First-Action isn't just a "delay". It's evidence of cognitive activity.

Fraud engines don't look for the fastest. They look for those who think.

Final thought:
True camouflage lies not in speed, but in pause.
Because in the world of machines, silence is the language of man.

Stay natural. Stay mindful.
And remember: in the world of fraud, the first 1.8 seconds are everything.