10 Tips for AI-Generated Captions with Style

AI-generated captions can save time, but they often miss the personal touch your brand needs to stand out. Here's how to guide AI tools to create captions that reflect your tone, engage your audience, and fit each platform's unique style. Key takeaways include:

• Define your brand voice: Set clear guidelines for tone, personality, and vocabulary.
• Write specific prompts: Include audience details, tone, platform, and goals.
• Tailor to platforms: Adjust style and length for Instagram, TikTok, LinkedIn, etc.
• Use keywords and hashtags: Ensure captions are discoverable and relevant.
• Generate multiple options: Create variations to find the best fit.
• Train AI with past captions: Share your top-performing examples for better results.
• Edit AI outputs: Add personal touches for a human feel.
• Leverage tools like Posterly: Simplify caption creation with advanced features.
• Match visuals with captions: Use tools like Nano Banana for consistency.
• Track performance: Use analytics to refine prompts and strategies.

I Know AI Wrote Your Instagram Caption (Here’s How to Fix It)

1. Set Your Brand Voice Before Using AI

AI tools are only as good as the instructions you give them. If you want captions that reflect your brand's personality instead of coming across as generic or robotic, you need to define your brand voice clearly. Without this foundation, AI will churn out captions that lack the essence of your brand. Setting clear guidelines from the start ensures AI can work with you - not against you.

Start by defining the "Big Three" elements of your brand: personality (how you connect with your audience), perspective (your unique beliefs and values), and tone (whether your communication style is formal, casual, witty, or polished). Think of your brand as a person - what role would they play in your audience's life? Are they the relatable best friend, the wise mentor, or the polished professional?

"AI isn't a mind reader (yet). If you want your brand to sound consistent, confident, and actually like you, you've got to teach it how." - Leah Messenger, Content Marketing Manager, Optimizely

Once you've nailed down your brand persona, create a vocabulary list. Include words and phrases that define your style, along with any jargon or slang to avoid. Share examples of your top-performing captions or tone-of-voice guidelines with the AI so it can replicate your style. You can even reference public figures or fictional characters that embody the voice you’re aiming for, giving the AI a clear benchmark.

Document all of this in a style guide. This ensures consistency across every piece of content, whether it’s crafted by a human or generated by AI. It’s worth the effort - 40% of consumers say memorable content helps a brand stand out, and 33% highlight a distinct personality as a key differentiator. Your brand voice isn’t just a detail; it’s the backbone of every successful caption.

2. Write Clear Prompts with Specific Details

When it comes to crafting captions, vague prompts lead to equally vague results. The key to getting captions that truly resonate with your brand lies in the level of detail you provide. According to Grammarly, prompts that are specific and nuanced produce far more relevant AI-generated responses.

Think of your prompt as a mini copywriting brief. Be clear about your audience (e.g., Gen Z skincare fans or B2B marketing professionals), the tone you want (witty and casual or professional and authoritative), the platform you're targeting (Instagram with its 2,200-character limit vs. X with only 280 characters), and your ultimate goal (like driving traffic to your website or starting a conversation).

"The more context and specifics you share with your AI model, the better equipped it will be to deliver what you need." - Grammarly

Here’s what every effective prompt should include:

• Visual descriptions: Be precise, like "a flat-lay of a coffee cup on a marble surface."
• Call-to-action: Specify what you want readers to do, such as "tag a friend" or "click the link in bio."
• Specific requirements: Mention details like the number of hashtags or particular emojis to use.
• Platform-specific hooks: For Instagram, where captions are truncated after two lines, ask for an attention-grabbing opening - like a surprising fact, a bold statement, or a provocative question.
• Tailored tone and keywords: For LinkedIn, where 4 out of 5 B2B leads come from social media, request a professional tone with industry-specific language to position yourself as a thought leader.

Providing this level of precision ensures that the captions AI generates stay aligned with the brand voice you’ve carefully defined in Tip 1.

For the best results, ask for 3–5 variations of a caption. Then, refine them further with follow-up prompts like "make this funnier" or "condense this for a TikTok description." These clear and detailed prompts set the stage for creating captions that truly embody your brand’s personality.

3. Adjust Style and Length for Each Platform

Every social media platform has its own unique "caption culture." LinkedIn users lean towards professional insights and thought leadership, while TikTok thrives on a casual, conversational vibe that feels raw and authentic. To make the most of your content, tailor your captions to fit the tone and style of each platform. Also, keep character limits and hook placement in mind to maximise impact.

For example, Instagram allows up to 2,200 characters, but only the first 125 characters are immediately visible. X (formerly Twitter) caps posts at 280 characters, while LinkedIn accommodates up to 3,000 characters. When using AI to generate captions, make sure to specify the platform and its constraints. For instance, you could request "a punchy one-liner for TikTok" or "a professional thought-leadership post for LinkedIn".

Start with a strong hook. Since platforms like Instagram truncate captions after the first 125 characters, make sure your most engaging content and call-to-action (CTA) appear right at the beginning. This is especially important as Instagram's average engagement rate has dropped to around 0.45%, making every visible word matter. Posts with engaging captions can boost engagement by as much as 15%.

"Great captions spark conversations and drive results." – Russ Tan, Vista Social

Additionally, tailor your CTAs to the platform. Use phrases like "Link in bio" for Instagram, "Retweet" for X, or direct prompts such as "Try this and let me know what you think" for TikTok. For longer messages on X, consider breaking them into threads for better readability. These adjustments not only align with platform-specific expectations but also reinforce the brand voice you’ve established.

4. Include Keywords and Hashtags in Your Prompts

Incorporating the right keywords and hashtags into your prompts is key to ensuring your captions perform well across social media platforms. When you ask AI to generate captions, include these elements intentionally. Social media algorithms rely on keywords and hashtags to categorise content and deliver it to the right audience. By embedding specific terms and hashtags in your prompts, you can keep captions focused, align them with your brand voice, and improve their chances of being discovered.

"Adding the right keywords to your social media captions can boost your social SEO strategy by helping your content appear in search and on explore pages." – Hootsuite

To get the most out of AI-generated captions, provide clear and detailed instructions. Instead of a vague prompt like "write a caption about fitness", try something more targeted: "Write an Instagram caption using keywords like 'morning workout routine' and 'fitness motivation' with hashtags #FitnessGoals and #DubaiGym." This level of precision ensures the caption is optimised for visibility and matches your brand's tone.

Instagram suggests using 3 to 5 hashtags per post for better reach, but studies indicate that posts with 7 to 30 hashtags often achieve the best engagement rates. To maximise impact, mix popular and niche hashtags in your prompts. While widely used tags like #fitness can expose your content to a large audience, niche hashtags such as #DubaiFitnessCoach help you connect with a more specific and engaged group. For example, you could prompt the AI with: "Include 2 popular hashtags and 3 niche hashtags related to healthy eating in the UAE."

Placement matters too. Include primary keywords in the first two lines of your caption, as many platforms truncate text beyond that point. For YouTube, ensure critical keywords are within the first 60 characters of the title. Be explicit in your instructions, such as: "Write a caption with 'sustainable fashion' in the opening sentence", to ensure important terms aren’t missed.

5. Create Multiple Options to Choose From

Once you've crafted clear and specific prompts, the next step is to generate multiple caption options. Relying on just one AI-generated caption could mean missing out on more fitting or creative alternatives that better match your brand's tone. By producing multiple variations, you can explore different styles, tones, and calls-to-action, helping you decide on the best fit. Some AI tools can even generate up to 20 variations at once, giving you a wide range to choose from for a single post. This is especially helpful for breaking out of creative slumps and uncovering fresh ideas.

"AI caption generators bring the double threat of creativity and consistency to ensure your social media posts are always unique and engaging." – Pictory Team

Having several options at hand also allows you to experiment with different strategies for engagement. For instance, you can test short, snappy captions aimed at quick scrollers versus longer, storytelling captions designed to build a deeper connection. This flexibility helps you tailor your content to suit the unique dynamics of each platform.

If the initial options don't hit the mark, tweak your prompt by adding more specific details about the visuals or target audience. Carefully review each AI-generated caption to ensure it reflects your brand's voice and avoids sounding overly mechanical. Use the AI's suggestions as a foundation, then personalise the best option with touches like humour or a relatable anecdote.

Rotating between different caption styles over time also keeps your content fresh and engaging for your audience. This method not only sustains interest but also opens the door for further AI-assisted improvements.

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6. Feed AI Your Previous Captions for Better Results

To get captions that truly reflect your brand's personality, start by training the AI with your best-performing examples. This helps the tool move beyond generic suggestions and align with your unique tone.

"Provide the tool with tone guidelines, sample captions, and brand personality details. This trains the algorithm to suggest captions that sound natural for your unique brand voice." – Pictory Team

Pick three to five captions that have resonated well with your audience and represent your brand’s style. Include these in your AI prompt with clear instructions, such as: “Use these captions as a reference to maintain our tone and style.” This gives the AI insight into specifics like emoji use, sentence flow, and industry-relevant language.

To enhance the process, pair these examples with your brand voice guidelines. Use descriptive words like “witty,” “inspiring,” or “casual” to help the AI fine-tune its suggestions to match your desired vibe.

7. Edit AI Output to Add Personality

Once you've guided AI with your best examples, take its output and make it your own. Think of AI as your brainstorming buddy - it gives you a starting point, but the magic happens when you refine it to reflect your brand's unique voice and style.

Start with an engaging hook. For instance, Instagram cuts captions after just two lines, so you need to capture attention fast. In September 2025, MeetEdgar illustrated this perfectly by comparing a bland AI-generated caption ("Start your Monday right with this productivity tip!") to a more relatable, humanised version:

"Who else hit the snooze button five times this morning? I know, been there... And that's the reason I want to share this productivity tip to help you start your Monday right..."

See the difference? The second caption sounds like a friend talking to you, while the first feels robotic and impersonal.

To make your content even more compelling, include specific visual details. Instead of saying "a nice coffee", describe "a steaming cup of coffee in a mug that says ‘But first, caffeine.’" Or swap "a beautiful sunset" with "a fiery orange sunset dipping below the horizon." Adding sensory elements - like the smell of fresh coffee or the sound of waves lapping against the shore - can make your captions more vivid and relatable.

When it comes to calls-to-action, ditch the generic "Comment below." Instead, try something interactive like "Tag a friend who can't function without coffee!" or "What's your secret to beating the Monday blues?" These tweaks invite more engagement and make your audience feel involved. And while emojis can add flair, keep them to around three to emphasise key points without overloading your post.

Small changes like these can have a big impact - social media posts with engaging captions often see up to a 15% boost in engagement compared to those that don’t. So, take the time to polish your AI-generated content, and watch your audience connect with your posts on a whole new level.

8. Use Posterly's AI Caption Assist for Styled Outputs

If you're looking to skip manual caption editing and jump straight to polished, styled captions, Posterly's AI Caption Assist has got you covered. This tool uses advanced natural language processing (NLP) and machine learning to craft text that mirrors your writing style, ensuring your captions stay consistent and on-brand.

Posterly simplifies the caption creation process with clear, tailored prompts. You can choose from seven tones - professional, excited, confident, witty, empowering, funny, or neutral - to match your brand's voice. Need to adjust for platform limits? You can also customise the caption length to be short, medium, or long. This feature seamlessly integrates into your workflow, making it easy to create captions that stand out.

Here’s how it works: Open your design in Posterly, click on "Publish", select "Social Media", and then choose "AI captions". Enter a specific prompt, like "playful caption for a sunrise over a coffee shop", and the AI will generate multiple options for you. You can even toggle hashtags on or off and explore additional variations by clicking "More Ideas".

With over 57,000 creators and teams already using Posterly, users have reported an average 114% boost in engagement. Alex T. from Trustpilot praises the platform, saying:

"Postly offers excellent pricing, fast and committed support, and leadership that delivers on promises".

Plus, Posterly ensures reliability with a 99.9% uptime SLA, so you can count on it to perform consistently.

While the AI does the heavy lifting, you can still make the captions uniquely yours. Add a personal touch, whether it’s an anecdote or a bit of your brand’s humour, to make the content truly resonate.

9. Use Nano Banana to Match Captions with Images

While Posterly takes care of crafting your captions, Nano Banana ensures your visuals are perfectly in sync. Matching the tone and style of your AI-generated captions with visuals can be tricky, but Nano Banana, an AI-powered image generation tool, simplifies the process by creating custom visuals that align seamlessly with your written content.

The process is straightforward. Charlie Hills, the founder of MarTech AI, developed a system that transforms LinkedIn posts into eye-catching visuals:

"I built a Gemini Gem that turns any LinkedIn post into a Nano Banana photoshoot. You drop in a selfie and your caption. It builds scroll-stopping visuals around your story".

This AI tool generates prompts that bring your text to life as engaging images.

Nano Banana is particularly good at maintaining character consistency, ensuring the person featured in your visuals looks the same across different posts. It can also pull colours, textures, and aesthetics from a reference photo and apply them to new images, keeping your brand's visual identity intact. For captions requiring specific text to appear in the image - like headlines on posters or product labels - Nano Banana Pro offers precise text rendering in high resolution.

To achieve professional results, include technical details in your prompts. Specify camera angles (e.g., "low-angle"), lighting (e.g., "golden hour"), and lens settings (e.g., "85mm f/1.4"). Additionally, choose the right aspect ratio for your platform: 16:9 for LinkedIn or YouTube, 9:16 for TikTok or Reels, and 1:1 for Instagram. These small adjustments ensure your visuals perfectly complement your captions.

Hills adds a practical note:

"Original photos will always be the best option. But if you don't have many, the workflow below will save you".

Nano Banana is a great tool for producing consistent, on-brand visuals that amplify the tone of your captions.

10. Track Performance and Adjust Your Approach

Understanding how your audience engages with your content is key to refining your strategy. Start by keeping an eye on core metrics like likes, comments, shares, and saves. These numbers give you a snapshot of how well your AI-generated tone resonates with your audience. On Instagram, saves are particularly meaningful - they show that users find your content valuable enough to revisit later.

Metrics like reach and impressions can help you gauge whether your hashtags are expanding your content's visibility. For captions with calls-to-action, tracking click-through rates (CTR) is essential to see if your prompts are effectively driving traffic to external links. These insights provide a foundation for tweaking your AI prompts and strategies.

Experimentation is another powerful tool. Try A/B testing different caption styles - such as a short, snappy version versus a longer, story-driven one - to see which earns more saves and shares. With Instagram's average engagement rate hovering around 0.45%, even slight improvements can create noticeable results.

Regularly reviewing analytics can help you identify trends and patterns. For example, if a particular framework like the "Problem-Agitate-Solution" method consistently outperforms others, you can use these insights to train your AI further. This helps refine its understanding of your brand's tone and personality.

As Russ Tan from Vista Social aptly puts it:

"Great captions don't just describe content - they start conversations, build communities, and drive real business results".

To maintain a balanced approach, follow the 80/20 rule: dedicate 80% of your captions to community-building and delivering value, while reserving 20% for promotional content. Use this data-driven approach to fine-tune your AI prompts and ensure your content strategy stays aligned with your brand's goals.

Conclusion

AI-generated captions can genuinely represent your brand when approached thoughtfully. Start by defining your brand's voice, crafting precise prompts, and ensuring that a human touch refines the final output.

Tools like Posterly make caption creation easier by offering features like brainstorming hooks, bulk scheduling, visual previews, and analytics - all in one platform. This streamlined process highlights how AI tools can complement your brand's unique style.

AI might provide a strong starting point, but it’s your personal input that shapes it into content that truly resonates. As BuildMyPlays puts it, "The best results come when you guide and refine AI-generated content with your human insight".

To maximise engagement, experiment with different caption lengths, tones, and calls-to-action. Leverage Posterly’s hashtag research to boost discoverability, and follow the 80/20 rule to balance community-focused and promotional posts. Remember, each platform has its own style when it comes to captions, so tailor your approach while staying true to your brand’s identity.

FAQs

How do I create a unique brand voice for AI-generated captions?

To create AI-generated captions that truly represent your brand's identity, start by clearly defining your brand voice. Think about its personality, perspective, and tone. If your brand were a person, how would it come across - friendly and approachable or more formal and professional? Decide on the emotional tone you want to convey, whether it’s confident, motivational, or something else, and clarify how your brand communicates with its audience.

Once you’ve established these traits, get specific. Outline your target audience, the type of vocabulary you prefer, your punctuation style, and even how often (if at all) emojis should be used. Don’t forget to include details relevant to the UAE, like using British spelling (e.g., "customise"), the correct date format (e.g., 02 January 2026), and the AED currency symbol. These elements help ensure the AI reflects your brand accurately.

With Posterly’s AI-assisted writer, you can save your brand-voice profile and even upload example captions to guide the AI. This ensures every caption matches your style, resonates with your audience, and saves you time - all while maintaining a consistent brand presence.

What should I include in prompts to create better AI-generated captions?

To create impactful prompts for AI-generated captions, it’s essential to provide precise and comprehensive instructions. Here’s what to include:

• Purpose and format: Clearly state the objective (e.g., “Highlight a limited-time AED 50 discount”) and any platform-specific guidelines (e.g., Instagram's 2,200-character limit for captions).
• Brand tone: Specify the desired style, whether it’s friendly, professional, or casual, and include any unique language or phrasing your brand consistently uses.
• Audience details: Share key demographic information such as age, location (e.g., UAE-based millennials), and cultural nuances (e.g., incorporating Ramadan traditions or iconic landmarks like the Dubai skyline).
• Key elements: Highlight must-have components like calls-to-action, relevant hashtags, emojis, or keywords (e.g., “#ShopLocal”).
• Stylistic preferences: Define spelling conventions (e.g., British English: “colour”), metric units (e.g., kilometres, kilograms), and temperature scales (Celsius) to ensure the content aligns with UAE norms.

When you input these details into Posterly’s AI caption generator, the tool can craft engaging, on-brand captions that resonate with your audience in the Emirates.

How can I align AI-generated captions with my brand's visuals and tone?

To make sure AI-generated captions reflect your brand's look and voice, start by giving the AI tool specific instructions. Share details about your brand's tone, preferred writing style, and visual aspects like colours, themes, and the mood you want to convey. This helps the AI create captions that align with your content's overall vibe.

After the captions are generated, take the time to review and tweak them. Adjust the tone, wording, and feel to ensure they stay true to your brand's identity. This extra step helps maintain a polished and engaging presence across all your platforms.