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Social Media

AI Image Caption Generator

Upload a photo and an AI model that can see images writes a caption about what is actually in it. One line of instructions sets the platform, tone, hashtags or language.

  • Free, three captions a day
  • Reads the photo itself
  • No account needed
Caption a photo
Example outputOne real run, Oct 2026
Photo
AI image of snowy peaks reflected in a misty lake at sunrise
Instructions
Instagram, first line under 10 words, one question at the end, 4 niche hashtags

Morning magic in the mountains! 🌄✨ Where do you find your peace? #MountainReflections #NatureLovers #ChasingSunrise #Wanderlust

The photo is an AI image from our AI image generator page, not a real place. Asked for niche hashtags, it still added broad ones like #Wanderlust: swap those for specific tags.

Caption your photo

One caption per run, written from what the model sees

3/3 captions left today

Blipix does not save your photo. Three captions a day per IP address; a failed run does not count.

Your caption

Waiting for a photo

Upload a photo, add an instruction line if you like, then press Generate Caption.

How it works

Photo in, caption out

  • 01

    Add a small photo

    JPG, PNG or WebP. The image travels inside the request, so shrink big phone shots to about 1,000 pixels wide before uploading.

  • 02

    Say where it is going

    Optional but worth it: name the platform, the tone, the length, any hashtags and anything the photo cannot show, like a name or a place.

  • 03

    Check, then copy

    Read it against the photo: AI can mislabel a landmark or a dish. Fix the first line, copy, and paste it into your post.

Instruction lines

Four jobs it handles well

The model is best when the picture carries the message and you need words that match it. Each card has the instruction line that works for that job.

  • Feed posts

    Try: “Instagram, first line under 10 words, one question at the end, 4 niche hashtags.”

  • Alt text

    Paste the result in the platform’s accessibility field.

    Try: “plain alt text, one sentence, describe only what is visible.”

  • Travel and event recaps

    Add the facts the photo cannot show.

    Try: “Facebook, warm tone, mention it was Lisbon in May.”

  • Product photos

    Check colors and materials it guesses.

    Try: “shop post, name the product as Linen Tote, two benefits, no hashtags.”

Better captions

Getting a caption worth posting from a photo

A vision model describes what it sees, and what it sees is rarely the point of the post. These habits close the gap between a caption about the pixels and a caption about the moment.

  1. Feed it the facts the picture hides

    The model can tell a beach from a mountain, not that this beach is where you got engaged. Put the who, where and why in the instructions line. One fact only you know beats three adjectives the AI found in the pixels.

  2. Write for the cut-off

    Feeds show only the first line or two before the “more” link, so that is where the reason to keep reading has to be. If the draft opens with a description (“A sunset over the bay”), move its most surprising detail to the front or ask for a question as the opening.

  3. Change the register for each app

    The same photo needs different words on different apps: warmer and longer for a Facebook group, a few words and an emoji on Snapchat. Name the platform in the instructions, or start from a topic with the Facebook caption generator or the Snapchat caption generator when there is no single photo to work from.

  4. Keep hashtags few and specific

    A few tags that name the actual subject (#lisbontrams rather than #travel) tell the platform and the reader what the post is about. Write the exact tags you want in the instructions, otherwise the model invents broad ones that thousands of other posts already use.

  5. Reuse the description for other formats

    Asking for “a literal description” gives you alt text, and the same description can seed new visuals: the image to prompt tool turns a photo into a generation prompt, and a three-sentence version of the story makes a script for a narrated Instagram Reel.

Keep going

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FAQ8 answers

Photo caption questions

Uploads, limits, privacy and getting better captions out of a picture.

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Yes. The image is sent to OpenAI’s GPT-4o mini, a model that can read pictures, with a short request to write a social caption. It picks up subjects, setting and mood well, but it can misread small text, brands or places, so check those before posting.

One line covering platform, tone, length and extras, for example: “Instagram, dry humor, under 20 words, end with a question, 3 hashtags.” Without instructions you get a generic caption. Names, locations and inside jokes only appear if you supply them.

Usually size or format. Photos over 5 MB are refused, and iPhone HEIC files are not read, so convert them to JPG first. A JPG around 1,000 to 1,500 pixels wide is plenty for a caption and uploads faster.

Three per day, counted per IP address, with the count resetting at midnight UTC. Each run returns one caption. To compare options, ask for “three short versions” in the instructions box so a single run gives you several.

Blipix does not save it: the page reads the file in your browser and forwards it to OpenAI to write the caption. Only your IP and the date are logged for the daily limit. Still, avoid uploading documents, IDs or photos of other people’s children.

Yes, ask for it in the instructions box, such as “write it in Brazilian Portuguese.” The model writes many languages fluently, but have a native speaker skim anything going on a brand account, since slang and idioms are where it slips.

The Instagram caption generator and the TikTok caption generator work from a topic you type. This tool starts from the picture itself, which helps when the photo is the story and you are not sure how to describe it.

Yes. Type “write plain alt text, one sentence, no hashtags” in the instructions. Alt text should describe what is visible for someone who cannot see it, so remove any jokes or calls to action the model adds.

Got the caption? Make the video version too.

Blipix turns a short script into a narrated vertical video with AI scenes, captions and music. Preview one on the free plan, export it on a paid one.

Try Blipix
  1. Script
  2. Voiceover
  3. Visuals
  4. Captions