---
schema_version: "1"
id: 06302caa5df794543749901684a3511af8023f01311f2678dcc65f1674c29695
title: Follow Size Guidance for CSP Headers
collection: admin
version: current
locale: en-us
portal_url: https://docs.salesforce.com/admin/current/en-us/release-notes/262-0-0/rn_security_csp_header_size_guidance.md
canonical_url: https://help.salesforce.com/s/articleView?id=release-notes.rn_security_csp_header_size_guidance.htm&release=262.0.0&type=5
source_site: help.salesforce.com
content_type: documentation
content_hash: 1837bc91c3f7d3e3c2daeb3845f05f8836ab187e24e542dcdb05777875498b4f
description: Provide a reliable experience when external sites serve content from your org in an iFrame. Target a Content Security Policy (CSP) header under 12 KB to reduce failures caused by infrastructure limits on HTTP header size. Customers report issues as headers approach 16 KB, and third-party processing can increase header size.
products:
  - Cross Cloud
release: "262"
---
# Follow Size Guidance for CSP Headers

Provide a reliable experience when external sites serve content from your org in an iFrame. Target a Content Security Policy (CSP) header under 12 KB to reduce failures caused by infrastructure limits on HTTP header size. Customers report issues as headers approach 16 KB, and third-party processing can increase header size.

**Where:** This change applies to Lightning Experience and Salesforce Classic in Contact Manager, Group, Professional, Enterprise, Performance, Unlimited, and Developer editions.