Send title and subtitle as JSON, get back a 1080x1080 square PNG ready for the Instagram feed.
Brand teams and content tools use the Instagram post image API to ship daily feed cards without booking a designer for every post. The 1080x1080 output is the safest default size on Instagram, since 1:1 reads cleanly across the home feed, profile grid, and reposts. You post the title, subtitle, and brand inputs as JSON, and the response holds a PNG hosted on i.html2img.com that you can schedule via Buffer, Later, or the Graph API.
curl -X POST https://app.html2img.com/api/v1/templates/instagram-square-post \
-H "X-API-Key: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"title":"Summer drop is live","subtitle":"Hand-printed tees, limited run of 200.","eyebrow":"NEW COLLECTION","cta":"Shop now \u2192 studioink.co","background_image_url":"https://picsum.photos/seed/insta-square/1080/1080","background_color":"#111111","accent_color":"#F472B6"}'
A single cURL call to render a Instagram Square Post as a PNG. Add "format": "pdf" to the payload to get a PDF instead. For the full PHP, Node and Python equivalents, plus every input the template accepts, see the
Instagram Square Post API reference.
Setting up your key is covered in the
authentication guide.
View the Instagram Square Post API reference: inputs, defaults, error responses and cURL, PHP, Node and Python code samples. Read the docs.
Marketing teams that publish weekly blog posts can pull the strongest quote from each article and render a square card for the Instagram feed. Connect your CMS publishing webhook to a script that posts to this endpoint with the quote, attribution, and brand inputs. The Instagram queue stays full without anyone designing manually. Northwind Studio publishes 3 quote cards per week through this exact pipeline.
Stores featuring a single product per feed post benefit from a clean square card with the product name, a CTA, and the brand mark. Generate one card per featured SKU during your weekly content planning, schedule across the week, and the feed grid maintains a visual rhythm. Riverside Bakery rotates 7 product highlights per week and the engagement on the cards beats their plain product photos by 2x.
Show producers post a square card per episode to push listeners to the latest drop. Render with the episode number, title, and host name, schedule the post for the morning the episode lands, and the show stays top-of-feed for subscribers who follow the podcast handle. The square format pairs cleanly with the dedicated podcast-episode-card template for the broader social rollout.
Communities running monthly meetups or virtual events post reminder cards in the lead-up. Render a card for each event with the date, title, and venue or join link, schedule across the week before, and turnout improves because attendees see the event multiple times in their feed. The Type Conference uses this template for the 8 weeks before the event for 12 cards.
Newsletter operators recap each issue on Instagram for the audience that follows on social rather than email. Render a card per issue with the issue number, headline topic, and CTA to subscribe, and the newsletter's social presence stays current with the weekly cadence. Wren Analytics ships these for its Tuesday digest and gains around 40 new email subscribers per Instagram post.
Matches the spec at Instagram feed image guidelines.
These specifications describe the default PNG output. The template can also return a PDF document with selectable text through the HTML to PDF API: set format to pdf in the request. See the format parameter docs for how PDF output behaves.
POST to the template endpoint with the values you want rendered. Authenticate with your API key.
The template is rendered server-side as a 1080x1080 PNG, or as a PDF document if you set format to pdf.
Cache it, embed it in your page, attach it to an email.
Instagram crops square posts in the profile grid view, so important content placed at the very edges gets clipped on grid display. Keep the focal area within the centre 80 percent of the canvas so it survives the grid crop.
A 16-pixel subtitle looks fine on the rendered image but blurs on a phone screen. Set type at 28 pixels or larger for body copy and 64 pixels or larger for headlines so the post is legible across iPhone and Android sizes.
Each card in a carousel uploads as its own image, so a 5-card carousel needs 5 endpoint calls. Generate them in a loop with consistent accent_color and brand inputs, and the carousel reads as a unified story rather than a mix of styles.
A quick summary of what the Instagram Square Post template accepts. The full reference, with example values and array shapes, is in the docs.
| Name | Type | Required |
|---|---|---|
title | string | Required |
subtitle | string | Optional |
eyebrow | string | Optional |
cta | string | Optional |
background_image_url | url | Optional |
logo_url | url | Optional |
background_color | string | Optional |
accent_color | string | Optional |
See the full inputs reference for descriptions, examples and validation rules.
Other templates in the social media category.
Bold share images sized for Facebook feed posts
Vertical 9:16 covers for Instagram and TikTok stories
Polished share images sized for LinkedIn feed posts
Vertical 2:3 pins with strong typography that stand out in feed
Render a tweet-style card from supplied data — avatar, body, image, metrics
Generate share-ready images sized for Twitter/X posts
High-contrast 16:9 thumbnails optimized for click-through
A starting point from each of the other two template categories.
See the full template gallery for every design grouped by category.
What size should an Instagram post be?
Square at 1080x1080 is the safest default. Instagram also supports 1080x1350 portrait (4:5) and 1080x566 landscape (1.91:1). This template renders the 1:1 size that displays consistently across feed, profile grid, and reposts. Approval decks that circulate as documents can request format: "pdf"; Instagram itself only accepts the image.
Will it look right in my profile grid?
Yes, the 1:1 ratio matches the profile grid cells exactly, with a small crop that Instagram applies. Keep the focal area inside the centre 80 percent of the canvas so the grid crop does not clip your title or logo.
Can I include text in the image?
Yes, but keep the type at 28 pixels or larger to stay readable on mobile screens. Posts with very small text fail Instagram's alt-text accessibility checks and underperform in feed delivery. The template enforces a sensible minimum.
Does it support carousel posts?
The endpoint renders one image per call. For a carousel, render multiple images and upload them as a multi-image post via the Instagram Graph API. Most teams render the carousel slides in a loop with consistent inputs so the carousel reads as a series.
Can I match my brand?
Yes, set accent_color, background_color, and logo_url. The accent applies to the eyebrow text and CTA, the background sets the surface color, and the logo sits in the corner. Pass the same values across renders so your feed stays visually consistent.
How do I post automatically?
Use the Instagram Graph API on your side to schedule or publish the rendered image. This template produces the artwork only, while the Graph API handles the actual post. Most teams render in advance and queue via Buffer, Later, or a custom scheduler.
25 renders a month on the free tier. See the pricing page for higher-volume plans.