Media & Limits
LinkedIn Ads media requirements per format, what the API cannot do, and the errors LinkedIn returns most often.
Use this page to look up a LinkedIn Ads media limit, check what LinkedIn's Marketing API does not expose, and match a recurring LinkedIn error to its cause. Files outside the limits below are rejected by LinkedIn, not compressed. Media URLs must be publicly accessible; LinkedIn (via Zernio) fetches and re-hosts them under the Company Page or ad account, and the media uploads guide covers hosting.
Media requirements
| Type | Format | Max size | Notes |
|---|---|---|---|
| Single image | JPEG, PNG, GIF | 5 MB | 1200 x 627 (1.91:1) recommended |
| Video | MP4 H.264/AAC | 500 MB | 3 seconds to 30 minutes, 75 KB minimum |
| Carousel | JPEG, PNG | 10 MB per card | 2 to 10 cards, 1080 x 1080 |
| Document | PDF, PPT, DOC | 100 MB | rendered as a swipeable document |
| Text ad logo | JPEG, PNG | 2 MB | 100 x 100 |
What you cannot do
LinkedIn's API does not expose:
- Profile-prefilled Lead Gen Form fields (EMAIL, FIRST_NAME, ...); Campaign Manager's UI only. API forms take
textandmultipleChoicequestions. - Lead webhooks. LinkedIn has no lead push, so poll
GET /v1/ads/leads(90-day retention). - A hard delete of a Lead Gen Form (archive only) or of a conversion rule (soft disable only).
- Appending to a contact-list audience: every upload is a full replace, and one upload carries at most 10,000 users.
- Daily time series on firmographic pivots: LinkedIn aggregates over the whole range (
timeGranularity: ALL). - Dynamic UTM parameters on Conversation, Message or Lead Gen Form ads.
- City, ZIP, metro, radius or income targeting: geo stops at country and region, and the professional facets carry the rest (targeting).
LinkedIn accepts the call and refuses the request when:
- The budget is below $10/day, or $100 lifetime on an inactive campaign.
- A conversion event is older than 90 days.
- A personal profile authored the post (Thought Leader Ads proper): the public Marketing API sponsors organization-authored posts only, and member posts return
422.
Common errors
LinkedIn's REST errors surface verbatim inside Zernio's platform_error envelope (error handling). The recurring ones:
| Error | Where | Cause and fix |
|---|---|---|
403 on create | Ads from scratch | The member lacks the Direct Sponsored Content Poster or Administrator role on the Page, or the Page is not associated with the ad account. |
403 linkedin_reconnect_required | Conversions API | The connection predates the rw_conversions scope. Reconnect the account. |
400 ads_connection_required | Lead responses | The connection lacks r_marketing_leadgen_automation. Reconnect the account. |
422 on reshare or sponsor | Thought-leader, boost | The post URN is an activity URN. Use the share or ugcPost id from "Copy link to post". |
SINMAIL_SENDER_NOT_APPROVED | Conversation ads | The sender is not approved for the ad account in Campaign Manager ("Manage message ad senders"), organization senders included. |
422 "The objective type is not supported" | Supply forecast | objectiveType is required in practice despite being documented optional. Pass any valid objective. |
404 on a dynamic-format creative | Follower, jobs, event ads | LinkedIn could not resolve the Page-side state (follow target, active job postings, a real Event). Fix the Page, not the payload. |
| Campaign quality score rejections, or stuck in review | Any | LinkedIn reviews every ad; a DRAFT or review state is normal for the first minutes to hours. |
Two behaviours that look like bugs and are not:
- A segment read right after an upload can come back empty. LinkedIn's audience builds are eventually consistent; re-read after a minute.
LinkedIn-Versiondeprecates monthly on LinkedIn's side. Zernio pins and rolls the version for you, so you never send it, and version churn is absorbed server-side.
Related
- Create ads and Creative formats: where each limit applies.
- Media uploads: host images and videos on Zernio.
- Error handling: the envelope every error uses.
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