Charts, OG images and PDFs from one API
Make charts and social images in your browser, or call one free API to turn data into chart PNGs, HTML into PDFs and pages into screenshots, with an MCP server for Claude, ChatGPT and Cursor.
An AI assistant calling the render_chart tool
Ask for the file you need
Say it to your assistant, or open the tool and do it yourself. Each line goes to the page that does it.
- Make a bar chart from this CSV
- Turn this JSON into a doughnut chart
- Plot weekly users per platform as lines
- Embed a live chart image in the README
- Design the OG image for this blog post
- Make an X card for tomorrow's launch
- Print this Markdown spec as a PDF with page numbers
- Create an invoice PDF for Acme, net 30
- Save this article as an A4 PDF
- Screenshot our pricing page at phone width
Every tool is free to use
Charts
Make charts in your browser or from JSON
- Chart maker Paste a table from Excel, Google Sheets, CSV or JSON, check the suggested chart, and download a clean PNG, SVG or PDF. It's free, with no sign-up and no watermark.
- Bar chart maker Enter your categories and values to get a bar chart with optional value labels, stacking or horizontal bars, then download it as PNG or SVG.
- Pie chart maker Type each slice's name and value, and the maker works out the percentages, labels the slices and adds a legend. Download PNG or SVG.
- Line graph maker Paste a table with one column per line and get a multi-line graph you can switch to an area chart and download as PNG or SVG.
- JSON to chart Paste JSON, such as an API response, an array of records or a Chart.js config. The maker finds the rows, lets you pick the label and value fields, and draws the chart right away.
- CSV to chart Copy cells from Excel or Google Sheets, or paste or open a CSV file. The first row names the columns, the label and number columns are detected, and the chart draws as you paste.
- Chart image API Send chart data as JSON in a URL or a POST body to https://render.cuelark.com/v1/chart and get a PNG or SVG image back, cached at the edge.
Social images
Open Graph and X card images
- OG image generator Pick one of 11 templates, type your text, apply your brand colors, font and logo, and download a 1200×630 Open Graph image or use its permanent URL as your og:image.
- X (Twitter) card generator Make a 1200×600 (2:1) summary_large_image picture for links shared on X and copy the twitter:card meta tags that make it show up.
- Open Graph image size Use 1200 × 630 pixels (1.91:1 aspect ratio), as a PNG or JPEG under 5 MB, with key text inside the center 1000 × 520 area.
HTML, URL and Markdown to PDF
- HTML to PDF API POST your HTML or a public URL to https://render.cuelark.com/v1/pdf and get back a PDF printed by real Chromium, with your CSS, fonts and page size.
- URL to PDF Paste a public web page link, choose Letter or A4, and get a PDF of the page as Chromium prints it, with no extension or sign-up.
- Markdown to PDF Write or paste Markdown, see it styled as you type, and export a clean Letter or A4 PDF with tables, code blocks, page breaks and a page-numbered footer.
- Invoice PDF generator Fill in the invoice fields, check the preview, and download a print-ready PDF. Developers can send the same HTML template to the PDF API to automate it.
Screenshots
URL and HTML to image
- Screenshot API POST a public URL to https://render.cuelark.com/v1/screenshot and get a PNG, JPEG or WebP of the page from real Chromium, at any viewport size or full page.
- Website screenshot Paste a link, choose desktop or mobile width and whether to capture the full page, and download a PNG or JPEG of the site.
- HTML to image API POST HTML and CSS to https://render.cuelark.com/v1/screenshot with the html field and a viewport size, and get back a PNG, JPEG or WebP image of it.
Set it up with one paste
Add the server URL to your AI client. There's no key to copy and nothing to install. Your assistant gets four tools: render_chart, social_card, html_to_pdf and screenshot_url.
{
"mcpServers": {
"cuelark-render": {
"url": "https://render.cuelark.com/mcp"
}
}
}$ claude mcp add --transport http cuelark-render https://render.cuelark.com/mcpPrefer plain HTTP? Read the Render API docs.
Share images that look designed
Every page on the web needs a 1200 × 630 Open Graph image. Type a title, pick brand colors and a logo, and get the right size for each platform.
Frequently asked questions
What is Cuelark Render?
A free set of browser tools plus one HTTP API and MCP server that turn data and web pages into files: chart images, Open Graph social cards, PDFs and website screenshots.
Is it free?
Yes. Chart and social card images are free within a per-minute rate limit. PDFs and screenshots use a real browser, so they're capped at 10 per day per IP without a key.
Do you store what I render?
No. Inputs and outputs aren't stored or logged. Only per-day counters keyed by a salted hash are kept, for the free limits.
Can AI assistants use it?
Yes. Add https://render.cuelark.com/mcp to Claude, ChatGPT, Cursor or VS Code and ask for a chart, a social card, a PDF or a screenshot. The tools return the file, a permanent image URL and alt text.
How is it different from QuickChart or Puppeteer?
Charts and cards are drawn in a Cloudflare Worker without a browser, so they return in milliseconds and every image has a cacheable URL. PDFs and screenshots run in managed Chromium, so you don't host a browser. Comparisons are on the compare pages.