# AI captions, hashtags and rewriting in the editor

AI captions writes a caption from your prompt, with the tone, length, hashtags and language you choose, or rewrites the one you have: rephrase, shorten, make punchier, fix spelling. It's unlimited on the plans sold today and uses no actions.

Last checked: Oct 8, 2026 on the live app. Source: https://heropost.ai/docs/ai/ai-captions/

**Where:** the sparkles icon (**AI captions**) in the corner of a caption box in the post editor.

## How it works

AI captions is the AI for writing, built into the post editor. Tell it what the post is about and it writes a caption in the tone, length and language you choose, with hashtags if you want them. Or let it rework what you've written: rephrase it, shorten it, make it punchier or fix the spelling and grammar. You read the result, then press **Apply** to put it in your post.

It's unlimited on the plans sold today and it doesn't use AI actions. It's separate from [Hero_Agent](/docs/ai/hero-agent/), which plans and saves whole posts for you: Hero_Agent and your connected AI tools run on monthly credits instead, because every task uses AI that costs money each time. See [AI actions](/docs/ai/actions-and-allowance/).

[Screenshot: The caption box in the post editor, with the AI captions icon highlighted]

## Write a new caption

1. In the post editor, click the sparkles icon (**AI captions**) in the corner of the caption box. With an empty box, it opens on **New Caption**.
2. Optional: pick a network under **Templates**, then click a ready-made prompt to copy it into **Prompt**. Replace the placeholder, such as {{ topic }}, with your subject.
3. Write or finish the **Prompt**, for example "Announce our autumn sale: 20% off all candles until Sunday, free shipping over $50".
4. Choose **Tone**, **Creativity**, **Words**, **Hashtags** and **Language** if you like (table below).
5. Press **Generate**. The caption types itself in on the **View/Edit** tab.
6. Edit it in the box, or use the rewrite buttons.
7. Press **Apply**. The caption replaces what was in the box.

[Screenshot: The New Caption tab with Instagram templates, the prompt and the Tone, Creativity, Words, Hashtags and Language options]

| Option | Choices | What it changes |
|---|---|---|
| **Templates** | Facebook, Instagram, LinkedIn, Google Business, X, Pinterest, YouTube, TikTok | Ready-made prompts for that network |
| **Tone** | Polite, Witty, Enthusiastic, Informational, Funny, Formal, Informal, Humorous, Serious, Optimistic, Motivating, Respectful, Assertive, Conversational, Casual, Professional, Smart, Nostalgic, Straightforward, Confident, Friendly | How it sounds |
| **Creativity** | Economic, Average, Good, Premium | From the most predictable wording to the most creative |
| **Words** | 25, 50, 100, 150, 200, 250, 500 | About how long it is |
| **Hashtags** | 1, 2, 3, 5, 10, 15, 20, 30 | How many hashtags it adds |
| **Language** | 84 languages | The language it writes in |

Every option can stay blank. If your browser is set to one of 15 widely used languages, **Language** starts on it; otherwise it starts on English. Left blank, it writes in the language of your prompt.

## Rewrite what you have

1. Click **AI captions** in a box that already has text. It opens on **View/Edit**.
2. Press **Rephrase**, **Make shorter**, **Make punchier** or **Fix spelling and grammar**. To rewrite into another language, pick it under **Language** first.
3. Each result is kept as a numbered version. Click the numbers to compare them.
4. Press **Apply** to use the version on screen, or **Cancel** to keep your original.

[Screenshot: The View/Edit tab with a caption, its character count, the rewrite buttons and two versions]

You can edit the text in the box before pressing a rewrite button: the rewrite starts from your edited text. **Tone**, **Creativity**, **Words** and **Hashtags** apply to new captions only.

## Where you'll find it

| Place | Fields |
|---|---|
| Post editor, **All** tab and network tabs | **Caption**, **First Comment**, YouTube **Description**, TikTok **Title**, Reddit **Text** |
| Automations | The **Custom Caption** field, when an automation's caption is set to Custom |
| **Caption Library** | The caption box when you create or edit a saved caption |

It isn't on the YouTube and Pinterest **Title** boxes, the Reddit **Caption** box, or link fields.

## Tips

- **Check the length.** AI captions doesn't keep to each network's character limit. Watch the character counter (for example 120/2,200 on Instagram) and use **Make shorter** if you're over.
- **Put the facts in the prompt.** AI captions writes from your prompt and the options you choose. It doesn't read your brand voice or the facts Hero_Agent has saved, so include prices, dates and links yourself.
- **Apply replaces the whole box.** To keep part of your text, edit the result before you apply it.
- **Nothing is posted.** **Apply** only fills in the field. You still schedule or publish the post as usual.

## Limits

| Plan | AI captions a month |
|---|---|
| Plans sold today (Growth, Pro, Agency), scheduler plans, Lifetime Starter, Growth and Agency, and the free trial | Unlimited |
| Some older lifetime deals | 3 |

- Each press of **Generate** or a rewrite button counts as one.
- AI captions are counted for each person, per calendar month (UTC).
- They never use Hero_Agent's actions or Hero_Photo's credits.

On [heropost.ai/pricing](https://heropost.ai/pricing/), every plan includes "Unlimited AI captions & hashtags".

## On a phone

The **AI captions** window fills the screen on phones and small tablets. On very narrow screens the **Templates** panel is hidden: write your own prompt instead.

## If it doesn't work

| What you see | What it means | What to do |
|---|---|---|
| "Something went wrong" | The caption couldn't be written this time. | Press **Generate** again. If it keeps happening, contact support with the time and what you typed. |
| **Time to Level up!** with "Upgrade to get unlimited access and unlock more features." | Your older lifetime deal includes 3 AI captions a month, and they're used. | Press **Upgrade** to see the plans, or wait for the 1st of next month. |
| **Generate** stays gray | The **Prompt** is empty. | Type a prompt or pick a template. |
| **Apply** stays gray | It's still writing, you're on the **New** tab, or the box is empty. | Wait for the text to finish, then apply it from **View/Edit**. |
| The caption is too long for the network | The AI doesn't count characters for you. | Press **Make shorter**, then check the counter. |
| No sparkles icon on a field | That field doesn't have the AI writing tools. | Write it by hand, or use AI captions on the caption box and copy the text. |

## Questions

**Does AI captions use my AI actions?**

No. It's the AI for writing included in your plan. Actions are only for Hero_Agent and connected AI tools.


**Which languages can it write in?**

84, chosen under **Language**. It can also rewrite a caption into another language from the **View/Edit** tab.


**Can my connected AI tool use AI captions?**

No. AI captions works in the Heropost app. ChatGPT, Claude and other connected tools write the copy themselves, then save it to Heropost.


**Does it know my brand?**

Not automatically: it writes from your prompt and options. For posts written from your brand voice and saved facts, ask [Hero_Agent](/docs/ai/plan-with-hero-agent/), or put the key points in your prompt.


**Can I get my original caption back after applying?**

**Cancel** before applying keeps your original. After **Apply**, the field holds the new text; open **AI captions** again and you'll start from that text.