Writing AI Prompts for Social Media: Platform-Specific Templates

Every platform punishes the same copy differently. LinkedIn truncates at 210 characters before "see more." X counts links as 23 characters regardless of length. Instagram buries captions behind a tap. TikTok rewards spoken hooks in the first 1.5 seconds. Facebook mixes link preview metadata with body text. Paste one generic "write a social post" prompt and you get five drafts that violate five rule sets. Platform-specific prompt architecture fixes that: one shared FACTS block, per-platform FORMAT overlays, character limits baked into the prompt, hook formulas per channel, hashtag rules, and batch variant generation. This guide covers LinkedIn, X, Instagram, TikTok, and Facebook templates, limits, hooks, hashtag strategy, batch variants for GPT-5.5, model routing, and FAQ.

Why one prompt fails across platforms

Generic prompt: Write a social post about our product launch. Output: LinkedIn-length essay with 12 hashtags dumped on X, emoji stacks on LinkedIn, and a TikTok script that reads like a press release. Models default to median internet tone — not your channel norms. Fix: FACTS block once, FORMAT block per platform. Never ask for "all platforms" in one unstructured request unless you specify independent FORMAT sections with hard limits.

The shared FACTS block

Paste product or campaign facts once. Models invent launch dates and stats without this.

FACTS (do not invent beyond this list):

Product/event: [name]

Launch date: [date or TBD]

Audience: [who cares on each platform — optional per-channel bullets]

Key message: [one sentence value prop]

Proof points: [2–4 verifiable bullets — stats, quotes, awards]

Link: [URL]

CTA: [single action — register, shop, read]

Banned: [competitor names, unapproved claims, pricing if not cleared]

Instruction: Use FACTS only. If a platform needs a fact not listed, write [NEED FACT] instead of inventing.

Master multi-platform prompt skeleton

FACTS: [block above]

BRAND VOICE: [2–3 lines or "match Sample A tone"]

Generate separate drafts for each PLATFORM section below. Do not reuse identical opening hooks across platforms.

PLATFORM: LINKEDIN

FORMAT: [LinkedIn overlay — see below]

PLATFORM: X

FORMAT: [X overlay]

Repeat per platform. GPT-5.5 handles batch variants cleanly when each FORMAT is explicit.

LinkedIn — limits and structure

Hook visible before "see more": ~210 characters (mobile varies; target 200 for safety).

Ideal post length: 1,200–1,800 characters for thought leadership; 600–900 for announcements.

Hashtags: 3–5 relevant; place at end or woven once — not stacked in the hook.

Link posts: native document or link in first comment strategy — prompt should specify which.

Tone: professional insight, first-person or we, line breaks every 1–2 sentences.

LinkedIn hook formulas

Hook formulas: (A) contrarian — [Common belief] is wrong. Here is what [audience] should do instead. (B) number lead — [N] lessons from [experience] that [outcome]. (C) story — [Timeframe] ago I [situation]. Today [result]. The shift. First 200 characters must stand alone as a complete curiosity gap. No hashtag in hook.

LinkedIn template

PLATFORM: LINKEDIN

FORMAT:

• Hook: max 200 chars, no hashtags
• Body: 3–5 short paragraphs, one idea per paragraph
• Proof: cite FACTS proof points
• CTA: one question or one action
• Hashtags: 3 at end, from list [provide approved tags]
• No emoji more than 2 total

OUTPUT: Post text only.

X (Twitter) — limits and structure

Standard post: 280 characters hard limit.

Premium/long posts: if applicable, note in FORMAT — otherwise assume 280.

Link: counts as 23 characters in standard counting.

Threads: specify thread count and per-tweet limit.

Tone: punchy, one idea, one link max unless thread.

X hook formulas

Hook formulas: (A) single stat — [Stat from FACTS]. That changes [implication]. (B) hot take — [Audience] does not need [X]. They need [Y]. (C) thread opener — I spent [time] on [topic]. [N] tweets on what actually works. Count characters including link as 23. If over 280, shorten and show final count.

X template

PLATFORM: X

FORMAT:

• Max 280 characters including link (link = 23 chars)
• Max 1 link from FACTS
• Max 2 hashtags, only if character budget allows
• No thread unless THREAD: true in task

OUTPUT: Final text + character count in parentheses.

Instagram — limits and structure

Caption limit: 2,200 characters; most engagement on first 125 visible before "more."

Hashtags: up to 30 allowed; 5–15 targeted often performs better than max spam.

Placement: caption end or first comment — specify in FORMAT.

Reels: spoken hook in first 3 seconds; caption supports but does not repeat video verbatim.

Tone: visual-first; describe what the image/video shows if FACTS include visual brief.

Instagram hook formulas

Hook formulas: (A) save-worthy — Save this if you [pain point]. (B) POV — POV: you finally [desired outcome]. (C) carousel slide 1 — [Bold claim in 8 words]. Line 1 max 125 chars for caption hook. Match emoji level to brand (0–3).

Instagram template

PLATFORM: INSTAGRAM

FORMAT:

• Line 1 hook: max 125 chars
• Body: skimmable lines, emoji per brand guide
• CTA: comment keyword or link in bio reference
• Hashtags: [N] from approved list at end

If REEL: add 10-second spoken script block separate from caption.

OUTPUT: Caption + optional script labeled SCRIPT:.

TikTok — limits and structure

Caption: 4,000 characters max; short captions often win.

Video: 15–60s typical; hook in first 1–2 seconds on-screen text + voice.

Hashtags: 3–5 mix of niche and broad; follow trending only if FACTS support relevance.

Tone: conversational, second person, written for speech not essay.

TikTok hook formulas

Hook formulas: on-screen (A) Stop scrolling if you [pain]. Spoken (B) Nobody tells you [secret] about [topic]. (C) I tried [thing] for [time]. Here is the truth. Output ON-SCREEN TEXT (max 8 words), SPOKEN SCRIPT (45–90 sec), CAPTION (under 150 chars).

TikTok template

PLATFORM: TIKTOK

FORMAT:

• ON-SCREEN TEXT: max 8 words, first frame
• SPOKEN SCRIPT: [duration] sec, short sentences, pause markers with ...
• CAPTION: max 150 chars + 4 hashtags
• CTA: follow or link in bio

OUTPUT: Three labeled sections. No press-release tone.

Facebook — limits and structure

Post text: 63,206 character max; practical limit 1–3 short paragraphs.

Link posts: og:title and description often pulled from page — prompt body should complement, not duplicate metadata.

Groups vs Page: specify audience familiarity (more context for cold Page, less for loyal Group).

Tone: community-oriented, questions drive comments.

Facebook hook formulas

Hook formulas: (A) question — [Audience], quick question: [relatable situation]? (B) local/community — [City/Community] — we just [news]. (C) event — [Day] at [time]: [what and why attend]. Optimize for comments — end with one specific question.

Facebook template

PLATFORM: FACEBOOK

FORMAT:

• Opening: 1–2 sentences, conversational
• Body: FACTS proof in plain language
• Link: one from FACTS with context sentence
• End: question to spark comments
• Hashtags: 0–2 optional, not required

OUTPUT: Post text only.

Hashtag strategy block

Add to every multi-platform prompt:

HASHTAG RULES:

Approved branded: [list]

Approved topical: [list]

Never use: [banned or overbroad tags]

Per platform caps: LinkedIn 3, X 2, Instagram [N], TikTok 4, Facebook 0–2

Instruction: Do not invent new hashtags unless labeled [SUGGESTED — APPROVAL REQUIRED].

Models recreate #Innovation and #AI on every draft without an approved list.

Character limit enforcement

Add global rule:

Before output, verify each platform draft against its character limit. If over, shorten and re-count. Show counts for X and LinkedIn hook only.

GPT-5.5 follows arithmetic better when asked to show count. Claude Opus 4.8 respects limits with FORMAT repetition at end of prompt.

Batch variants workflow

TASK: Generate 3 variants per platform with different hooks (A/B/C formulas). Label Variant 1/2/3. Same FACTS, different hooks only — not different claims.

Use GPT-5.5 for 15-piece batch (5 platforms × 3 variants). Human picks one per channel.

PromptMake /text: paste FACTS + one PLATFORM FORMAT → 3/day guest, 5/day registered. Build library of winning FORMAT presets.

Batch variant prompt

FACTS: [block]

PLATFORMS: LinkedIn, X, Instagram

VARIANTS: 3 per platform

RULES:

• Hooks must use different formulas (contrarian, stat, story)
• Same proof points across variants
• Output markdown table: Platform | Variant | Text | Char count

Registered tier supports full batch in one session; guests should run one platform per generation.

Carousel and thread overlays

LinkedIn carousel: add SLIDES: 8 | Slide 1 headline max 6 words | Slide 8 CTA

X thread: add THREAD: 5 tweets | Tweet 1 hook | Tweet 5 CTA link

Instagram carousel: add SLIDES: 5 | on-image text per slide max 12 words

Keep carousel prompts separate from single-post batch — different structure.

Visual brief injection

For Instagram and TikTok, add VISUAL BRIEF:

Shot 1: [description]

Text overlay: [words]

Brand colors: [if any]

Model writes script matching visuals — reduces generic caption drift.

Compliance and claims

Add: No health, income, or comparative claims unless in FACTS with citation. Add [NEED LEGAL] for superlatives (#1, best, guaranteed).

Regulated industries: human review before publish. Prompts control format — not legal clearance.

Platform algorithm context (2026)

LinkedIn rewards dwell time and meaningful comments — hooks that promise a payoff keep readers past see more. X favors native engagement over link-only posts; put the insight in the tweet, not just the URL. Instagram Reels get discovery lift; static posts need stronger save/share CTAs. TikTok completion rate matters — script to a tight arc with payoff before second 15. Facebook Groups outperform Page posts for discussion — adjust question hooks for community familiarity. Mention these in FORMAT when TASK includes GROWTH GOAL: [awareness | engagement | clicks].

Optional SCHEDULING block:

Post date: [holiday, event tie-in]

Timezone audience: [primary]

Platform priority: [which channel leads campaign]

Model adjusts urgency and references — not fake timeliness.

Model routing for social copy

GPT-5.5: batch variants, character counts, tables of 15 drafts

Claude Opus 4.8: LinkedIn long-form, nuanced hooks, brand voice

Gemini 3.1 Pro: multi-platform in one prompt with long FACTS + style guide

Gemini 3.5 Flash: first-draft TikTok scripts and short X posts — human shortens to limit

Do not use Flash alone for compliance-sensitive claims.

Before vs after: generic vs platform-specific

Weak: Write Instagram and LinkedIn posts for our webinar.

Output: Identical paragraph with 30 hashtags on both.

Strong: FACTS block + separate FORMAT for each + hook char limits + hashtag caps.

Output: LinkedIn thought-leadership hook, Instagram 125-char line with Reel script.

Repurposing without copy-paste

Repurpose prompt:

SOURCE DRAFT: [LinkedIn post that performed well]

TASK: Repurpose to X and TikTok — same facts, new hooks, platform FORMATs applied. Do not truncate LinkedIn text — rewrite natively.

Native rewrite beats "shorten the LinkedIn post."

UTM and link discipline

LINKS:

Base: [URL]

UTM pattern: ?utm_source=[platform]&utm_medium=social

Prompt: append correct utm per platform. One link per post unless thread.

Emoji and formatting rules

EMOJI: [none | sparse max 2 | liberal]

LINE BREAKS: [yes for LinkedIn/Instagram | minimal for X]

BANNED: rocket emoji launch cliché, fire emoji hype — unless brand guide allows

Stops models defaulting to 🚀 on every launch post.

Influencer and employee advocacy overlay

ADVOCACY MODE: Reposting employee or creator — preserve their first-person voice. FACTS block adds: Speaker: [name/role], Disclosure: [#ad if paid]. FORMAT per platform unchanged but tone shifts to personal anecdote + one brand fact. Never require employees to use identical corporate hook — provide 3 FACTS bullets they choose from.

After campaign, paste top performer: WINNING PATTERN: [paste post] | TASK: New FACTS but match hook structure and rhythm. Closes loop without copying stale content.

Common failures

One prompt, no FORMAT overlays → five wrong-length drafts

Hashtag soup on LinkedIn → algorithmic noise

X post over 280 because model counted wrong → always request count

TikTok script written to read not speak → always request spoken script

Identical hooks across platforms → audience fatigue

FACTS missing → invented statistics

PromptMake workflow

Save FACTS + per-platform FORMAT as /text inputs. Guest: 3 generations/day — run highest-priority platform first. Registered: 5/day — batch variants or second platform.

Iterate hooks on one platform before expanding batch.

FAQ

Should I generate all platforms in one prompt?

Yes if each has explicit FORMAT and limits. No if you paste a vague "all social posts" request — quality drops after platform three.

How do I enforce X character limits?

Require final count in output and link-as-23 rule. Shorten in a second pass if over: Shorten to 275 chars max, preserve CTA.

How many hashtags on Instagram in 2026?

Prompt for 5–15 targeted tags from an approved list. Thirty generic tags signal spam to users even if allowed.

LinkedIn hook — characters or words?

Characters (~200) before see more. Words vary — count characters in prompt instruction.

Best model for batch social variants?

GPT-5.5 for volume and labeling. Opus for flagship LinkedIn thought leadership.

TikTok script too long?

Cap SPOKEN SCRIPT at 120 words for 60s. Add WPM: 150 conversational.

Can AI pick trending hashtags?

Only suggest with [SUGGESTED] flag. Trends without relevance hurt reach. Human approves.

Facebook vs Instagram — same caption?

No. Facebook allows longer context; Instagram front-loads hook. Repurpose natively.

How do I avoid invented launch dates?

FACTS block with explicit dates and [NEED FACT] rule. Audit every date in output.

Guest vs registered PromptMake limits?

Guests: 3 /text generations per day. Registered: 5/day. Plan platform priority accordingly.

Related articles

ai-prompts-consistent-brand-voice, prompt-engineering-marketing-copy-aida-pas, perfect-prompt-formula-seo-content — voice, ad angles, long-form repurposing

Bottom line

Social media prompting is FORMAT engineering: shared FACTS, per-platform limits, hook formulas, hashtag rules, and batch variants.

GPT-5.5 for batches, Opus for flagship LinkedIn, Flash for TikTok first drafts. Count characters on X. Never invent facts outside FACTS.