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Free Growth Tool
Tweet Virality Tester
& Engagement Predictor
Test hooks, formatting, and scannability inside a live simulated X timeline. Predict likes, replies, and impressions calibrated to your follower count before you post.
- Live simulated X feed
- Client-only media (never uploaded)
- Follower-scaled power-law baseline
- Dual-engine AI + 61 rule heuristics
Draft Composer174 / 280
34 words·6 line breaks·~9s read
Your Follower Count10k followers
Timeline Profile & Avatar
@
Client-only · Never uploaded
Test the hook before the feed tests it for you
Free simulated X (Twitter) timeline tester that scores your tweet hooks, formatting, readability, and predicts follower-calibrated engagement before you post.
Why it matters
On X (formerly Twitter), the first line and the visual shape of your post decide whether a reader stops scrolling or swipes past. Once you hit publish, the algorithm measures early dwell time, click-through, and replies within the first 15 minutes. Testing your draft in isolation fails to capture how it actually looks when sandwiched between high-stimulus posts in a busy feed.
Tweet Tester lets you preview your draft inside an authentic simulated X feed alongside sample posts. You can attach images or video previews with 100% privacy: files are rendered locally in your browser and never uploaded to any server.
What the tool does
The scoring engine evaluates your draft across five vital dimensions: Hook Impact, Craft & Social Proof, Format & Scannability, Value & Utility, and Emotional Resonance. It checks for algorithmic penalties such as external outbound links in main posts, reply-bait phrases ('say YES', 'comment below'), and excessive hashtags.
Engagement predictions are calibrated to your account size using an organic power-law curve (0.04 * Followers^0.78), multiplied by your tweet's virality index. You get estimated ranges for Likes, Replies, Reposts (with low-confidence tagging), and Impressions, along with actionable 'What Helped' and 'What Hurt' insights.
Terms worth knowing
- Simulated Timeline
- A visual mock of the X home feed that surrounds your draft with typical posts, allowing you to test readability, visual hierarchy, and mobile fold cutoffs.
- Hook Impact
- The power of the opening sentence (first 1–2 lines) to create curiosity, contrast, or immediate intrigue within 0.8 seconds.
- Follower-Scaled Baseline
- An empirical power-law engagement formula where larger accounts experience natural engagement rate decay.
- Outbound Link Penalty
- Algorithmic reach reduction applied to tweets containing external URLs in the initial post rather than a follow-up reply.
- Scannability & Spacing
- Strategic use of line breaks, short paragraphs, and bullet points to maximize reading completion on mobile screens.
- Client-Only Media
- Images or videos previewed locally via browser object URLs, keeping draft media completely private.
Frequently asked questions
Short answers for the decisions that usually come up after a first run.
Is Tweet Tester free to use?
Yes. Tweet Tester is completely free with no sign-up, account creation, or credit card required.
Are my draft tweets or images uploaded to a server?
Draft text is sent securely to the scoring engine to evaluate hooks and metrics. Attached images or videos remain entirely client-side in your browser using local object URLs and are never uploaded or stored.
How are predicted likes, replies, and impressions calculated?
Predictions use an organic engagement baseline calibrated to your follower count via an empirical power-law formula (Baseline Likes = 0.04 * Followers^0.78). This baseline is then scaled by your draft's calculated Virality Score (0–100) and industry-standard engagement distribution ratios.
Why are external links penalized in the score?
The X recommendation algorithm significantly downranks posts with outbound URLs because they take users off-platform. Best practice is to post the link in the first reply or auto-DM instead.
What is reply-baiting and why does it hurt the score?
Phrases like 'Comment YES below' or 'Drop a reply to get the PDF' trigger automated engagement spam filters and lower organic distribution. Algorithmic scoring favors authentic questions and conversation starters.
Does Tweet Tester work for long-form / X Premium posts?
Yes. It supports drafts up to 4,000 characters, tracking where the fold cut-off occurs so you can ensure your critical hook appears before the 'Show more' prompt.