We added a new Turbo mode for our 🤖 /document/thumbs Robot. It emits page thumbnails as soon as they are ready instead of batching them at the end, so downstream Steps can start work earlier. This can reduce end-to-end time for multi‑page PDFs by up to ten times, depending on your workflow.

What is Turbo Mode?

Turbo mode lets Transloadit parallelize or stream work so results become available earlier. We first introduced it for our 🤖 /video/encode and 🤖 /video/concat Robots, and are now bringing similar benefits to document thumbnailing. See our Turbo Mode FAQ to find out how it works.

How it works for documents

Turbo mode is enabled by default for document thumbnails. Turbo mode allows the 🤖 /document/thumbs Robot to emit a result for each page as soon as that page is processed. If you prefer batched results, you can opt out per Step by setting turbo: false.

Leaving Turbo mode enabled means:

  • Faster pipelines: subsequent Steps (for example, image post-processing or storing) can begin while later pages are still being rendered.
  • Much faster resizing: when you specify width and/or height, extracted pages are resized in parallel on remote machines rather than queued sequentially on a single machine (concurrency of 1). This results in a dramatic speedup that scales linearly with the number of pages.
  • Predictable ordering: results are still sorted by page. You can also inspect meta.thumb_index to determine a page’s index.

This streaming behavior is especially useful for document viewers that need to show page previews as soon as possible, or pipelines in which every second matters between ‘upload’ and ‘first usable preview’.

When to use it (and when not to)

✅ Time-sensitive workflows: choose Turbo mode if you want the fastest possible time-to-first- preview, or if downstream work can run per page.

❌ Cost-sensitive workflows: for some pricing scenarios, earlier per‑page emission can be treated similarly to handling multiple inputs. If your primary goal is minimizing cost, consider opting out by setting turbo: false. For details, see our pricing docs.

Why is it enabled by default?

In our analysis of common setups, document thumbnails are small and inexpensive compared to video and other workloads. Enabling Turbo by default delivers meaningful latency gains while having a negligible impact on most invoices. If minimizing cost is your top priority, you can always opt out by setting turbo to false.

Example Assembly

Below is a minimal example that converts a multi‑page PDF into 600‑px wide page thumbnails and stores them with an index in the file path. Turbo mode is enabled by default; no additional parameter is needed. To opt out, set turbo: false. Keep an eye on meta.thumb_index for page‑aware filenames.

{
  "steps": {
    "thumbs": {
      "use": ":original",
      "robot": "/document/thumbs",
      "width": 600,
      "resize_strategy": "fit"
    },
    "store": {
      "use": "thumbs",
      "robot": "/s3/store",
      "path": "docs/${file.original_basename}/page-${meta.thumb_index}.${file.ext}"
    }
  }
}

Availability

Turbo mode for document thumbnails is available today and enabled by default. If you want to opt out account‑wide, please reach out to mailto:hello@transloadit.com and we will help you set it up.

Learn more and try it

Enjoy, and use responsibly!