AI Captions for Instagram
Upload a photo, get a ready-to-post caption with hashtags in seconds
PhotoScanr analyzes your image and writes captions optimized for engagement, complete with relevant hashtags and alt text
Captions Under 2,200 Characters
AI writes captions that fit within Instagram's character limit. The first line is crafted as a hook since it's all users see before tapping "more."
Hashtag Strategy Built In
Get a curated mix of high-volume and niche hashtags. Instagram currently recommends 3-5 targeted hashtags rather than filling all 30 slots.
Image Dimension Check
Flags whether your image fits Instagram's recommended ratios: 4:5 portrait (1080x1350), 1:1 square (1080x1080), or 1.91:1 landscape (1080x608).
Alt Text for Accessibility
Generates descriptive alt text so visually impaired users can understand your content. Instagram supports custom alt text on every post.
Batch Multiple Photos
Preparing a week of content? Upload multiple images and get captions for each. Great for planning carousel posts or a content calendar.
One-Click Copy
Copy the full caption with hashtags, or just the hashtags separately. Paste directly into Instagram or your scheduling tool.
Why Good Captions Matter on Instagram
The First Line Is Everything
Instagram truncates captions after about 125 characters in the feed. Users only see your first sentence before the "more" button. If that line doesn't grab attention, the rest of your caption goes unread.
PhotoScanr's AI understands this and writes a compelling opening line based on what's actually in your photo, followed by context and a call to action below the fold.
Hashtags Have Changed
Instagram's own recommendation shifted from "use all 30" to "use 3-5 highly relevant hashtags." Stuffing irrelevant tags can actually hurt your reach because the algorithm interprets it as spam.
PhotoScanr selects hashtags based on your actual image content, mixing broader discovery tags with specific niche tags that match what's in the photo.
Alt Text Helps More Than Accessibility
Instagram's custom alt text field (found under Advanced Settings when posting) serves two purposes. It makes your content accessible to screen reader users, and it gives Instagram's algorithm more context about your image.
Most creators skip this field entirely, which means Instagram relies on its own automatic image recognition instead of your description. Writing your own gives you more control.
Consistency Is the Hard Part
Writing one great caption is easy. Writing five per week, every week, is where most creators burn out. The blank text box becomes the bottleneck, not the photography.
PhotoScanr eliminates the blank-page problem. Upload your photo, get a starting point in seconds, then edit it to match your voice. Faster than writing from scratch every time.
Instagram Photo Optimization Tips
Use 4:5 Portrait for Feed Posts
Portrait orientation (1080x1350) takes up more screen space in the feed than square or landscape, giving your post more visual weight as users scroll. This is the maximum vertical space Instagram allows for standard feed posts.
Add Line Breaks to Captions
Walls of text get skipped. Use line breaks and spacing to make your caption scannable. Separate your hook, your story, your call-to-action, and your hashtags into distinct blocks. You can add line breaks by using the return key or invisible characters between paragraphs.
Write Alt Text on Every Post
When creating a post, tap "Advanced Settings" then "Write Alt Text." Describe what's in the image in plain language. This helps visually impaired followers experience your content and gives Instagram better context for recommendations. If you skip it, Instagram generates its own, which is usually less accurate.
Target Niche Hashtags Over Broad Ones
A hashtag like #photography has billions of posts. Your content gets buried instantly. A tag like #torontosunsetphotography has far fewer posts but a much more engaged audience. PhotoScanr analyzes your specific image to suggest tags that match what you actually photographed.
Carousel Posts Get More Reach
When a user swipes but doesn't engage, Instagram may re-show the post starting from the next slide. This gives carousels multiple chances to appear in the feed. Use PhotoScanr to generate captions for each image in your carousel, then combine the best elements into one cohesive caption.
How It Works
Upload Your Photo
Drag and drop or browse to select your image. Works with JPG, PNG, WebP, and HEIC files.
AI Analyzes Your Image
Google Gemini AI identifies subjects, scenes, mood, colors, and composition, then writes content matched to what's in the photo.
Get Caption, Hashtags, and Alt Text
Receive a complete caption with an engaging first line, relevant hashtags, and descriptive alt text, all within Instagram's character limits.
Copy and Post
One-click copy puts everything on your clipboard. Paste into Instagram, edit to match your voice, and publish.
Frequently Asked Questions
What's the ideal Instagram caption length?
Instagram allows up to 2,200 characters per caption. However, the feed only shows the first ~125 characters before truncating with a "more" button. The most important thing is that your first line is compelling. After that, length depends on your content: educational posts tend to perform well with longer captions (800-1,500 characters), while visual-first posts can work with shorter ones.
How many hashtags should I use?
Instagram officially recommends 3-5 relevant hashtags. Using more isn't penalized, but irrelevant tags can signal spam to the algorithm. PhotoScanr generates hashtags based on your actual image content, so they're always relevant to what you're posting.
Should I put hashtags in the caption or comments?
Either works. Instagram has confirmed there's no difference in reach between the two approaches. Many creators put hashtags in a first comment to keep the caption clean. PhotoScanr gives you a separate copy button for hashtags so you can paste them wherever you prefer.
What image size works best for Instagram posts?
For feed posts, 1080x1350 pixels (4:5 portrait) takes up the most screen space. Square images use 1080x1080. Landscape images use 1080x608 (1.91:1). For Stories and Reels, use 1080x1920 (9:16). PhotoScanr checks your image dimensions and flags any sizing issues.
Try It Free
Upload a photo and get an Instagram-ready caption in seconds. No signup required.
Generate Instagram Caption →5 free analyses per day • No account needed • Results in seconds
Average analysis time per photo
Advanced image understanding
Your photos are never saved on our servers
Instagram is a trademark of Meta Platforms, Inc. PhotoScanr is not affiliated with, endorsed by, or sponsored by Meta. PhotoScanr generates content for use on Instagram and other platforms.