Previews

Render an ad the way Meta renders it with GET /v1/ads/{adId}/preview. Render a creative that does not exist on an ad yet with POST /v1/ads/preview.

Both return Meta's <iframe> HTML, one snippet per requested format. Meta only.

Preview an existing ad

Call GET /v1/ads/{adId}/preview with the Zernio ad id and up to 10 comma-separated formats. Omitting formats returns DESKTOP_FEED_STANDARD.

import Zernio from '@zernio/node';

const zernio = new Zernio();

const { data: rendered } = await zernio.adcreatives.getAdPreviews({
  path: { adId: '66d4a1b2c3e4f5a6b7c8d9e2' },
  query: { formats: 'DESKTOP_FEED_STANDARD,INSTAGRAM_STORY' }
});

for (const preview of rendered.previews) console.log(preview.format, preview.html);

Response (200):

{
  "adId": "66d4a1b2c3e4f5a6b7c8d9e2",
  "previews": [
    { "format": "DESKTOP_FEED_STANDARD", "html": "<iframe src=\"https://www.facebook.com/ads/api/preview_iframe.php?d=...\" width=\"540\" height=\"690\" scrolling=\"yes\" style=\"border: none;\"></iframe>" },
    { "format": "INSTAGRAM_STORY", "html": "<iframe src=\"https://www.facebook.com/ads/api/preview_iframe.php?d=...\" width=\"320\" height=\"580\" scrolling=\"yes\" style=\"border: none;\"></iframe>" }
  ]
}

html is null for a format Meta returned no preview for.

Preview before you create

Call POST /v1/ads/preview with accountId, adAccountId and exactly one of:

• existingCreativeId, a creative from an earlier create or the library
• creativeSpec, a raw Meta creative spec, forwarded verbatim

formats is optional here too, defaulting to [DESKTOP_FEED_STANDARD], and takes up to 10 values.

const { data: draft } = await zernio.adcreatives.generateAdPreviews({
  body: {
    accountId: '66b2e19d8c3f5a7e9d0b1c2d',
    adAccountId: 'act_1234567890',
    existingCreativeId: '120250000000000005',
    formats: ['DESKTOP_FEED_STANDARD', 'INSTAGRAM_STORY']
  }
});

Response (200):

{
  "previews": [
    { "format": "DESKTOP_FEED_STANDARD", "html": "<iframe src=\"https://www.facebook.com/ads/api/preview_iframe.php?d=...\" width=\"540\" height=\"690\" scrolling=\"yes\" style=\"border: none;\"></iframe>" },
    { "format": "INSTAGRAM_STORY", "html": "<iframe src=\"https://www.facebook.com/ads/api/preview_iframe.php?d=...\" width=\"320\" height=\"580\" scrolling=\"yes\" style=\"border: none;\"></iframe>" }
  ]
}

To preview a design that is not in the ad account yet, replace existingCreativeId with creativeSpec.

link_data.picture takes a plain public image URL, so no upload is needed. That makes this the cheap way to put a live preview inside a creative editor:

{
  "creativeSpec": {
    "object_story_spec": {
      "page_id": "811889972008357",
      "link_data": {
        "link": "https://example.com",
        "message": "Primary text",
        "name": "Headline",
        "picture": "https://cdn.example.com/i.jpg",
        "call_to_action": { "type": "LEARN_MORE", "value": { "link": "https://example.com" } }
      }
    }
  }
}

Formats

formats passes through to Meta's ad_format enum, which has about 60 values that change over time. The ones you reach for most:

Rendering the snippet

Each entry in previews[] is an <iframe> pointing at a signed Meta URL. Drop it into your UI so the user sees the real ad in the real placement without opening Ads Manager.

The URL is short-lived. Fetch previews when the user opens the panel instead of caching them.

The frame has fixed dimensions per format. Scale it with CSS transform rather than changing the width and height attributes.

If it fails

A 400 on an unknown format carries Meta's own message, which lists every valid ad_format value and is always current:

{
  "error": "Invalid parameter: ad_format must be one of DESKTOP_FEED_STANDARD, MOBILE_FEED_STANDARD, ...",
  "type": "platform_error",
  "platform": "meta"
}

Pick a value from that list.

A 429 means Meta's rate limit. Wait and retry.

Related

• Creative library: the creative ids existingCreativeId accepts.
• Creatives: the shapes a preview can render.
• Render pre-create ad previews and Render previews of an existing ad: every field.