diff --git a/index.js b/index.js
index b7c22ef..b550358 100644
--- a/index.js
+++ b/index.js
@@ -26,7 +26,7 @@ const injectLottie = `
  *
  * Must pass either `path` or `animationData`.
  *
- * `output` may either be any of the following:
+ * `output` may be any of the following:
  *   - an image to capture the first frame only (png or jpg)
  *   - an image pattern (eg. sprintf format 'frame-%d.png' or 'frame-%012d.jpg')
  *   - an mp4 video file (requires FFmpeg to be installed)
diff --git a/readme.md b/readme.md
index 424eb70..26dbe4c 100644
--- a/readme.md
+++ b/readme.md
@@ -43,15 +43,10 @@ await renderLottie({
   height: 128
 })
 
-// Render the first frame of the animation as a JPEG with specific dimensions
-// Note: the lottie-web renderer defaults to 'xMidyMid meet' so the resulting
-// image will retain its original aspect ratio in the middle of the viewport and
-// be padded with whitespace (or transparent regions if using png)
+// Render the first frame of the animation as a JPEG image
 await renderLottie({
   path: 'fixtures/bodymovin.json',
-  output: 'preview.jpg',
-  width: 640,
-  height: 480
+  output: 'preview.jpg'
 })
 ```
 
@@ -59,14 +54,49 @@ Note that all CSS styles are specified via the [JS CSS syntax](https://www.w3sch
 
 ## API
 
-TODO
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+### [renderLottie](https://git@github.com/:transitive-bullshit/puppeteer-lottie/blob/56235fed59f7a84656f0e8508275cdfc73396dfb/index.js#L60-L382)
+
+Renders the given Lottie animation via Puppeteer.
+
+Must pass either `path` or `animationData`.
+
+`output` may be any of the following:
+
+-   an image to capture the first frame only (png or jpg)
+-   an image pattern (eg. sprintf format 'frame-%d.png' or 'frame-%012d.jpg')
+-   an mp4 video file (requires FFmpeg to be installed)
+-   a GIF file (requires Gifski to be installed)
+
+Type: `function (opts): Promise`
+
+-   `opts` **[object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)** Configuration options
+    -   `opts.output` **[string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** Path or pattern to store result
+    -   `opts.animationData` **[object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)?** JSON exported animation data
+    -   `opts.path` **[string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Relative path to the JSON file containing animation data
+    -   `opts.width` **[number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)?** Optional output width
+    -   `opts.height` **[number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)?** Optional output height
+    -   `opts.jpegQuality` **[object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)** JPEG quality for frames (does nothing if using png) (optional, default `90`)
+    -   `opts.quiet` **[object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)** Set to true to disable console output (optional, default `false`)
+    -   `opts.deviceScaleFactor` **[number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)** Window device scale factor (optional, default `1`)
+    -   `opts.renderer` **[string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** Which lottie-web renderer to use (optional, default `'svg'`)
+    -   `opts.rendererSettings` **[object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)?** Optional lottie renderer settings
+    -   `opts.puppeteerOptions` **[object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)?** Optional puppeteer launch settings
+    -   `opts.gifskiOptions` **[object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)?** Optional gifski settings (only for GIF outputs)
+    -   `opts.style` **[object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)** Optional JS [CSS styles](https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Properties_Reference) to apply to the animation container (optional, default `{}`)
+    -   `opts.inject` **[object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)** Optionally injects arbitrary string content into the head, style, or body elements. (optional, default `{}`)
+        -   `opts.inject.head` **[string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Optionally injected into the document <head>
+        -   `opts.inject.style` **[string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Optionally injected into a <style> tag within the document <head>
+        -   `opts.inject.body` **[string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** Optionally injected into the document <body>
+    -   `opts.browser` **[object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)?** Optional puppeteer instance to reuse
 
 ## Related
 
-- [puppeteer-lottie-cli](https://github.com/transitive-bullshit/puppeteer-lottie-cli) - CLI for this module.
-- [puppeteer](https://github.com/GoogleChrome/puppeteer) - Headless Chrome Node API.
-- [awesome-puppeteer](https://github.com/transitive-bullshit/awesome-puppeteer) - Curated list of awesome puppeteer resources.
-- [lottie](http://airbnb.io/lottie) - Render After Effects animations natively on Web, Android and iOS, and React Native.
+-   [puppeteer-lottie-cli](https://github.com/transitive-bullshit/puppeteer-lottie-cli) - CLI for this module.
+-   [puppeteer](https://github.com/GoogleChrome/puppeteer) - Headless Chrome Node API.
+-   [awesome-puppeteer](https://github.com/transitive-bullshit/awesome-puppeteer) - Curated list of awesome puppeteer resources.
+-   [lottie](http://airbnb.io/lottie) - Render After Effects animations natively on Web, Android and iOS, and React Native.
 
 ## License