Upload images to HubSpot with the Files API

Why go through the File Manager

HubSpot’s File Manager is the portal’s media library: everything you insert into emails, pages, landing pages and blog posts is served from there, through HubSpot’s CDN. SocialCutter generates centered-crop versions at the exact dimensions of each destination and returns a public URL per output; if those images will live inside HubSpot, it is better to upload them to the File Manager than to link external URLs: you manage them, reuse them and index them with the rest of your assets.

The boundary matters: SocialCutter generates images, it does not publish. HubSpot will not publish to Instagram or LinkedIn for you from the File Manager either; it only stores and serves the file.

Requirements: Private app and scopes

Create a Private app under Settings → Integrations → Private apps and tick the Files API scopes:

Scope	What it is for
files	Read, upload and archive files and folders
files.ui_hidden.read	Access hidden files that do not show in the public listing

The token starts with pat- and travels in the Authorization: Bearer pat-… header. The complete Files API reference, with the current scopes and fields, lives at https://developers.hubspot.com/docs/api-reference/latest/files/guide.

Upload a file by multipart

POST /files/v3/files accepts multipart/form-data. One file per request:

curl -s -X POST "https://api.hubapi.com/files/v3/files" \
  -H "Authorization: Bearer pat-your_token" \
  -F "file=@instagram-post.jpg" \
  -F "folderPath=/socialcutter" \
  -F 'options={"access":"PUBLIC_INDEXABLE"}'

Field	Required	Description
file	Yes	The binary to upload
folderId or folderPath	One of the two	Destination folder; do not upload to the root
fileName	No	Final name; generated from the content if omitted
options	No	JSON with access and, optionally, ttl (1 day to 1 year)

The 201 response carries id, path, url, defaultHostingUrl, access, width, height and isUsableInContent. Keep the id and the url: they are what you use later in the email editor or the image picker.

Upload from a URL with import-from-url

When SocialCutter already returns URLs, you do not need to download and re-upload by hand. HubSpot imports from a URL asynchronously:

curl -s -X POST "https://api.hubapi.com/files/v3/files/import-from-url/async" \
  -H "Authorization: Bearer pat-your_token" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://cdn.socialcutter.theboomer.dev/out/twitter-post.jpg",
    "access": "PUBLIC_INDEXABLE",
    "folderPath": "/socialcutter",
    "duplicateValidationStrategy": "REJECT",
    "duplicateValidationScope": "EXACT_FOLDER"
  }'

The 202 response returns a task id. You poll the status with GET /files/v3/files/import-from-url/async/tasks/{taskId}/status, which answers PENDING, PROCESSING, COMPLETE or CANCELED. With COMPLETE the file is already in the File Manager.

Version note: HubSpot has been moving the Files API to versioned routes (from files/v3 to schemes such as files/2026-09), and scope names have changed between versions. Before hard-coding routes in your code, confirm the current route and scopes in the official documentation linked above.

Access levels and where each file can be used

access	Can it be inserted into emails, pages and landing pages?
PUBLIC_INDEXABLE	Yes, and it can also be indexed by search engines
PUBLIC_NOT_INDEXABLE	Yes, but not indexed
PRIVATE	Not directly: it needs a signed URL and isUsableInContent is false
SENSITIVE	No: meant for data, not for content

If the image is going into an email or a landing page, use public access. A private file will not render in the email because the mail client cannot sign the URL.

HubSpot recommended sizes

These are the sizes HubSpot publishes for the places images are used inside the portal. For the exact dimensions that SocialCutter generates per social network, the reference is the internal measures guide (linked below).

HubSpot placement	Recommended size	Ratio
Image inside an email	600 px wide	Variable (template width rules)
Email header	600x200	3:1
Blog featured image	1200x628	~1.91:1
Social share image	1200x630	1.91:1
Blog thumbnail	400x400	1:1
Landing hero / full-width	1920x1080 (≥1200 px wide)	16:9
Site banner	2500x625	4:1
Author image	500x500	1:1

HubSpot sources: its social media sizes guide (https://blog.hubspot.com/marketing/ultimate-guide-social-media-image-dimensions-infographic) and its website image sizes guide (https://blog.hubspot.com/website/image-size-for-website). Watch the fine differences: HubSpot’s social share is 1200x630 and its blog featured image 1200x628; the closest SocialCutter destination is facebook + post (1200x630). If you need a size the catalogue does not produce, crop it separately.

Flow: from SocialCutter to the File Manager

1. Process the master: POST /api/v1/images/process with source and destinations.
2. Walk the outputs array and fire an import-from-url/async per URL.
3. Wait for COMPLETE per task and collect the final url.
4. Insert that URL into the email, landing page or blog post.

import time, requests

HUB = {"Authorization": "Bearer pat-your_token"}
BASE = "https://api.hubapi.com/files/v3/files/import-from-url/async"

def upload(url, folder="/socialcutter"):
    r = requests.post(BASE, headers={**HUB, "Content-Type": "application/json"},
                      json={"url": url, "access": "PUBLIC_INDEXABLE", "folderPath": folder},
                      timeout=30)
    r.raise_for_status()
    task = r.json()["id"]
    while True:
        s = requests.get(f"{BASE}/tasks/{task}/status", headers=HUB, timeout=30).json()
        if s.get("status") in ("COMPLETE", "CANCELED"):
            return s
        time.sleep(2)

for out in outputs:            # outputs comes from SocialCutter
    print(out["platform"], upload(out["url"]))

Cost

Concept	Value
Cost per processing	1 use per destination (platform and format)
Duplicate destinations in the same request	Not charged twice
HubSpot File Manager upload	No extra cost, within the portal limits
SocialCutter plans	0, 3, 9 and 29 EUR, with API and MCP included

A request for Instagram post + LinkedIn post + X post uses 3 SocialCutter uses and produces 3 HubSpot uploads.

Common errors

Error	What is really happening	What to do
401/403 on upload	The token lacks the files scope	Add the scope in the Private app and regenerate the token
Image does not show in the email	It was uploaded as PRIVATE	Upload with public access (PUBLIC_INDEXABLE or PUBLIC_NOT_INDEXABLE)
400 on the multipart upload	Missing folderId/folderPath or the folder does not exist	Create the folder first, or use import-from-url, which can create it
429	Portal rate limit	Add retries with exponential backoff
Duplicate name	An identical file already exists in the folder	Use duplicateValidationStrategy: RETURN_EXISTING or overwrite
The source URL will not import	HubSpot could not download the image	Check the URL is public and reachable without a session

Next steps

• API guide with curl: Process images with the API from the terminal
• Python: Process images with the SocialCutter API from Python
• No-code: Automate image resizing with Zapier, Make or n8n
• Strategy: Automating social media images: the 4 real paths
• Sizes: Social media sizes: dimensions and ratios
• API documentation: https://docs.socialcutter.theboomer.dev