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TikTok Algorithm 2025: How It Decides What to Show

11/9/20257-9 min
TikTok Algorithm 2025: How It Decides What to Show

What you will learn:

  1. How TikTok algorithm works in 2025
  2. Main ranking signals
  3. First 3 seconds and CTR
  4. Retention and its impact
  5. Engagement Rate and comments
  6. View velocity
  7. How to trick algorithm (spoiler: you can't)

How TikTok algorithm works in 2025

TikTok algorithm is not magic or randomness. It's a mathematical model that predicts whether user will like the video.

How it works:

  1. Test audience — video shown to 200-500 random users
  2. Behavior analysis — algorithm watches how they react
  3. Decision — if metrics good, video goes further into recommendations
  4. Scaling — process repeats with each new audience

Algorithm doesn't know if your video is good. It only knows how people react to it.

Main ranking signals

1. Retention

What % watched to the end. If less than 50% — algorithm considers video uninteresting.

2. Early ER

Likes, comments, saves in first 1-2 hours. More is better.

3. Rewatches

If user rewatches video — strong quality signal.

4. CTR

What % users clicked on video after showing in feed.

5. Completion velocity

How fast first 1-3K views are gained with high retention.

First 3 seconds and CTR

Why first 3 seconds are critical:

User decides in 1-3 seconds whether to watch further. If hook weak — scroll away, retention drops.

What affects CTR:

  • Thumbnail — bright, contrasting, with text
  • First frame — movement, emotion, intrigue
  • Title — short, with question or shock

Test: If CTR less than 10% — problem in thumbnail or first frame.

Retention and its impact

Retention is main algorithm metric.

Algorithm looks not only at average retention, but retention by sections:

  • 0-25% — hook works or not
  • 25-50% — pacing holds or loses
  • 50-75% — content interesting or boring
  • 75-100% — finale strong or weak

How to improve retention:

  • Cut all pauses
  • Change angle every 3-5 sec
  • Add captions with keywords
  • Speed up speech to 1.1-1.2x

Engagement Rate and comments

ER = (likes + comments + saves) / views × 100%

Normal ER for TikTok is 5-10%. If less than 3% — problem in content or CTA.

Why comments matter more than likes:

Comment requires more effort than like. Algorithm values this higher.

How to increase comments:

  • Ask specific question at end
  • Create discussion (agree/disagree)
  • Reply to comments in first hour

View velocity

Completion velocity — how fast video gains first 1-3K views with high retention.

If in first hour video got 1000 views with 60% retention — algorithm gives another 10K. If retention 30% — stops promotion.

What affects velocity:

  • Posting time (when your audience online)
  • First comments and likes (from subscribers)
  • Hook quality and retention

How to trick algorithm (spoiler: you can't)

Myths that don't work:

  • View botting — algorithm sees bots and bans
  • Hashtags — almost no impact on reach
  • Posting time — important but not critical
  • Video length — doesn't matter, retention matters

What actually works:

  • Strong hook in first 3 seconds
  • High retention (50%+)
  • Early ER (comments in first hour)
  • Quality content

Check your video metrics and discover retention, ER in our free tool.

Download videos without watermark on SaveFlix.space for cross-posting.

TikTok Algorithm 2025: How It Decides What to Show • SaveFlix