Web page PDF rendering done right. Microservice for rendering receipts, invoices, or any content. Packaged to an easy API.
โญ๏ธ Features:
- Converts any URL or HTML content to a PDF file or an image (PNG/JPEG)
- Rendered with Headless Chrome, using Puppeteer. The PDFs should match to the ones generated with a desktop Chrome.
- Sensible defaults but everything is configurable.
- Single-page app (SPA) support. Waits until all network requests are finished before rendering.
- Easy deployment to Heroku. We love Lambda but...Deploy to Heroku button.
- Renders lazy loaded elements. (scrollPage option)
- Supports optional
x-api-key
authentication. (API_TOKENS
env var)
Usage is as simple as https://url-to-pdf-api.herokuapp.com/api/render?url=http://google.com. There's also a POST /api/render
if you prefer to send options in the body.
๐ Why?
This microservice is useful when you need to automatically produce PDF files for whatever reason. The files could be receipts, weekly reports, invoices, or any content.
PDFs can be generated in many ways, but one of them is to convert HTML+CSS content to a PDF. This API does just that.
๐ Shortcuts:
Local setup is identical except Express API is running on your machine and requests are direct connections to it.
-
By default, page's
@media print
CSS rules are ignored. We set Chrome to emulate@media screen
to make the default PDFs look more like actual sites. To get results closer to desktop Chrome, add&emulateScreenMedia=false
query parameter. See more at Puppeteer API docs. -
Chrome is launched with
--no-sandbox --disable-setuid-sandbox
flags to fix usage in Heroku. See this issue. -
Heavy pages may cause Chrome to crash if the server doesn't have enough RAM.
-
Docker image for this can be found here: https://github.com/restorecommerce/pdf-rendering-srv
- For security reasons the urls have been restricted and HTML rendering is disabled. For full demo, run this app locally or deploy to Heroku.
- The demo Heroku app runs on a free dyno which sleep after idle. A request to sleeping dyno may take even 30 seconds.
The most minimal example, render google.com
https://url-to-pdf-api.herokuapp.com/api/render?url=http://google.com
The most minimal example, render google.com as PNG image
https://url-to-pdf-api.herokuapp.com/api/render?output=screenshot&url=http://google.com
Use the default @media print instead of @media screen.
https://url-to-pdf-api.herokuapp.com/api/render?url=http://google.com&emulateScreenMedia=false
Use scrollPage=true which tries to reveal all lazy loaded elements. Not perfect but better than without.
Render only the first page.
Render A5-sized PDF in landscape.
Add 2cm margins to the PDF.
Wait for extra 1000ms before render.
https://url-to-pdf-api.herokuapp.com/api/render?url=http://google.com&waitFor=1000
Download the PDF with a given attachment name
https://url-to-pdf-api.herokuapp.com/api/render?url=http://google.com&attachmentName=google.pdf
Wait for an element matching the selector input
appears.
https://url-to-pdf-api.herokuapp.com/api/render?url=http://google.com&waitFor=input
Render HTML sent in JSON body
NOTE: Demo app has disabled html rendering for security reasons.
curl -o html.pdf -XPOST -d'{"html": "<body>test</body>"}' -H"content-type: application/json" http://localhost:9000/api/render
Render HTML sent as text body
NOTE: Demo app has disabled html rendering for security reasons.
curl -o html.pdf -XPOST -d@test/resources/large.html -H"content-type: text/html" http://localhost:9000/api/render
To understand the API options, it's useful to know how Puppeteer is internally used by this API. The render code is quite simple, check it out. Render flow:
-
page.setViewport(options)
where options matchesviewport.*
. -
Possibly
page.emulateMedia('screen')
ifemulateScreenMedia=true
is set. -
Render url or html.
If
url
is defined,page.goto(url, options)
is called and options matchgoto.*
. Otherwisepage.setContent(html, options)
is called where html is taken from request body, and options matchgoto.*
. -
Possibly
page.waitFor(numOrStr)
if e.g.waitFor=1000
is set. -
Possibly Scroll the whole page to the end before rendering if e.g.
scrollPage=true
is set.Useful if you want to render a page which lazy loads elements.
-
Render the output
- If output is
pdf
rendering is done withpage.pdf(options)
where options matchespdf.*
. - Else if output is
screenshot
rendering is done withpage.screenshot(options)
where options matchesscreenshot.*
.
All options are passed as query parameters. Parameter names match Puppeteer options.
These options are exactly the same as its POST
counterpart, but options are
expressed with the dot notation. E.g. ?pdf.scale=2
instead of { pdf: { scale: 2 }}
.
The only required parameter is url
.
Parameter | Type | Default | Description |
---|---|---|---|
url | string | - | URL to render as PDF. (required) |
output | string | Specify the output format. Possible values: pdf , screenshot or html . |
|
emulateScreenMedia | boolean | true |
Emulates @media screen when rendering the PDF. |
enableGPU | boolean | false |
When set, enables chrome GPU. For windows user, this will always return false. See https://developers.google.com/web/updates/2017/04/headless-chrome |
ignoreHttpsErrors | boolean | false |
Ignores possible HTTPS errors when navigating to a page. |
scrollPage | boolean | false |
Scroll page down before rendering to trigger lazy loading elements. |
waitFor | number or string | - | Number in ms to wait before render or selector element to wait before render. |
attachmentName | string | - | When set, the content-disposition headers are set and browser will download the PDF instead of showing inline. The given string will be used as the name for the file. |
viewport.width | number | 1600 |
Viewport width. |
viewport.height | number | 1200 |
Viewport height. |
viewport.deviceScaleFactor | number | 1 |
Device scale factor (could be thought of as dpr). |
viewport.isMobile | boolean | false |
Whether the meta viewport tag is taken into account. |
viewport.hasTouch | boolean | false |
Specifies if viewport supports touch events. |
viewport.isLandscape | boolean | false |
Specifies if viewport is in landscape mode. |
cookies[0][name] | string | - | Cookie name (required) |
cookies[0][value] | string | - | Cookie value (required) |
cookies[0][url] | string | - | Cookie url |
cookies[0][domain] | string | - | Cookie domain |
cookies[0][path] | string | - | Cookie path |
cookies[0][expires] | number | - | Cookie expiry in unix time |
cookies[0][httpOnly] | boolean | - | Cookie httpOnly |
cookies[0][secure] | boolean | - | Cookie secure |
cookies[0][sameSite] | string | - | Strict or Lax |
goto.timeout | number | 30000 |
Maximum navigation time in milliseconds, defaults to 30 seconds, pass 0 to disable timeout. |
goto.waitUntil | string | networkidle0 |
When to consider navigation succeeded. Options: load , domcontentloaded , networkidle0 , networkidle2 . load - consider navigation to be finished when the load event is fired. domcontentloaded - consider navigation to be finished when the DOMContentLoaded event is fired. networkidle0 - consider navigation to be finished when there are no more than 0 network connections for at least 500 ms. networkidle2 - consider navigation to be finished when there are no more than 2 network connections for at least 500 ms. |
pdf.scale | number | 1 |
Scale of the webpage rendering. |
pdf.printBackground | boolean | false |
Print background graphics. |
pdf.displayHeaderFooter | boolean | false |
Display header and footer. |
pdf.headerTemplate | string | - | HTML template to use as the header of each page in the PDF. Currently Puppeteer basically only supports a single line of text and you must use pdf.margins+CSS to make the header appear! See #77. |
pdf.footerTemplate | string | - | HTML template to use as the footer of each page in the PDF. Currently Puppeteer basically only supports a single line of text and you must use pdf.margins+CSS to make the footer appear! See #77. |
pdf.landscape | boolean | false |
Paper orientation. |
pdf.pageRanges | string | - | Paper ranges to print, e.g., '1-5, 8, 11-13'. Defaults to the empty string, which means print all pages. |
pdf.format | string | A4 |
Paper format. If set, takes priority over width or height options. |
pdf.width | string | - | Paper width, accepts values labeled with units. |
pdf.height | string | - | Paper height, accepts values labeled with units. |
pdf.fullPage | boolean | - | Create PDF in a single page |
pdf.margin.top | string | - | Top margin, accepts values labeled with units. |
pdf.margin.right | string | - | Right margin, accepts values labeled with units. |
pdf.margin.bottom | string | - | Bottom margin, accepts values labeled with units. |
pdf.margin.left | string | - | Left margin, accepts values labeled with units. |
screenshot.fullPage | boolean | true |
When true, takes a screenshot of the full scrollable page. |
screenshot.type | string | png |
Screenshot image type. Possible values: png , jpeg |
screenshot.quality | number | - | The quality of the JPEG image, between 0-100. Only applies when screenshot.type is jpeg . |
screenshot.omitBackground | boolean | false |
Hides default white background and allows capturing screenshots with transparency. |
screenshot.clip.x | number | - | Specifies x-coordinate of top-left corner of clipping region of the page. |
screenshot.clip.y | number | - | Specifies y-coordinate of top-left corner of clipping region of the page. |
screenshot.clip.width | number | - | Specifies width of clipping region of the page. |
screenshot.clip.height | number | - | Specifies height of clipping region of the page. |
screenshot.selector | string | - | Specifies css selector to clip the screenshot to. |
Example:
curl -o google.pdf https://url-to-pdf-api.herokuapp.com/api/render?url=http://google.com
All options are passed in a JSON body object. Parameter names match Puppeteer options.
These options are exactly the same as its GET
counterpart.
Body
The only required parameter is url
.
{
// Url to render. Either url or html is required
url: "https://google.com",
// Either "pdf" or "screenshot"
output: "pdf",
// HTML content to render. Either url or html is required
html: "<html><head></head><body>Your content</body></html>",
// If we should emulate @media screen instead of print
emulateScreenMedia: true,
// If we should ignore HTTPS errors
ignoreHttpsErrors: false,
// If true, page is scrolled to the end before rendering
// Note: this makes rendering a bit slower
scrollPage: false,
// Passed to Puppeteer page.waitFor()
waitFor: null,
// Passsed to Puppeteer page.setCookies()
cookies: [{ ... }]
// Passed to Puppeteer page.setViewport()
viewport: { ... },
// Passed to Puppeteer page.goto() as the second argument after url
goto: { ... },
// Passed to Puppeteer page.pdf()
pdf: { ... },
// Passed to Puppeteer page.screenshot()
screenshot: { ... },
}
Example:
curl -o google.pdf -XPOST -d'{"url": "http://google.com"}' -H"content-type: application/json" http://localhost:9000/api/render
curl -o html.pdf -XPOST -d'{"html": "<body>test</body>"}' -H"content-type: application/json" http://localhost:9000/api/render
HTML to render is sent in body. All options are passed in query parameters.
Supports exactly the same query parameters as GET /api/render
, except url
paremeter.
Remember that relative links do not work.
Example:
curl -o receipt.html https://rawgit.com/wildbit/postmark-templates/master/templates_inlined/receipt.html
curl -o html.pdf -XPOST -d@receipt.html -H"content-type: text/html" http://localhost:9000/api/render?pdf.scale=1
Health check endpoint used for monitoring if the service is still up and running.
curl -XGET http://localhost:9000/healthcheck
To get this thing running, you have two options: run it in Heroku, or locally.
The code requires Node 8+ (async, await).
Scroll this readme up to the Deploy to Heroku -button. Click it and follow instructions.
WARNING: Heroku dynos have a very low amount of RAM. Rendering heavy pages may cause Chrome instance to crash inside Heroku dyno. 512MB should be enough for most real-life use cases such as receipts. Some news sites may need even 2GB of RAM.
First, clone the repository and cd into it.
-
cp .env.sample .env
-
Fill in the blanks in
.env
-
npm install
-
npm start
Start express server locally -
Server runs at http://localhost:9000 or what
$PORT
env defines
- Node 8+ (async, await), written in ES7
- Express.js app with a nice internal architecture, based on these conventions.
- Hapi-style Joi validation with express-validation
- Heroku + Puppeteer buildpack
- Puppeteer to control Chrome