Files and Attachments are two different ways Salesforce stores documents linked to records. Attachments are the older method, now largely deprecated, where files are tied directly to a single record and stored in a separate data silo. Salesforce Files (also called ContentDocument) is the modern standard, offering a centralized, flexible storage model that works across your entire org. Below, we break down the key differences so you know exactly what you’re working with and what to do about it.
Salesforce moved away from Attachments because the model was too rigid and created storage and usability problems at scale. Each Attachment was locked to a single record, stored in a separate system, and offered no sharing, versioning, or collaboration capabilities. As organizations grew and document volumes increased, this approach became a bottleneck rather than a feature.
The shift to Salesforce Files addressed several structural limitations. Attachments counted against a separate storage limit that was harder to manage, they couldn’t be linked to multiple records, and they weren’t accessible through Lightning Experience in any meaningful way. Salesforce officially discouraged new Attachment use and redirected development investment entirely to the Files framework, which is now the foundation for all document-related functionality on the platform.
Salesforce Files use a centralized content storage model, while Attachments use a record-level storage model. With Files, every uploaded document is stored once as a ContentDocument and can be linked to multiple records without duplicating storage. Attachments, by contrast, are stored per record, meaning the same document uploaded to three records consumes storage three times.
This distinction matters practically when you’re dealing with high volumes of documents. In document-intensive industries like real estate or media, where contracts, project files, and assets are often relevant across multiple records, the Files model dramatically reduces storage overhead. Attachments also counted against a different storage bucket, which made capacity planning more complicated. Files consolidate everything into a single, more predictable storage framework that’s easier to monitor and manage.
Yes, Salesforce Files can be linked to multiple records simultaneously without creating duplicate copies. A single ContentDocument can be associated with an account, a related opportunity, and a contact all at once. Attachments cannot do this. Each Attachment belongs to exactly one parent record and cannot be shared or referenced from anywhere else in the org.
This cross-record linking is one of the most practical advantages of the Files model. Think about a master services agreement in a sales workflow: it’s relevant to the account, the opportunity, and possibly a case. With Files, you upload it once and link it where it’s needed. With Attachments, you’d need to upload three separate copies, which creates version confusion and wastes storage. The document management features that Salesforce has built around Files all depend on this centralized model.
Salesforce Files support version control, file sharing with external users via Content Deliveries, integration with Salesforce libraries, and real-time collaboration through Office 365. Attachments support none of these. They are static uploads with no version history, no sharing mechanism, and no connection to any collaborative workflow.
Here’s a quick comparison of what Files bring to the table that Attachments simply can’t match:
For teams working across departments or with external partners, these capabilities aren’t nice-to-haves. They’re the difference between a document system that supports real work and one that just stores files passively.
Yes, migrating existing Attachments to Salesforce Files is strongly recommended if you’re running Lightning Experience or planning to. Attachments are not supported in Lightning the way Files are, and Salesforce has made clear that the Attachment object is a legacy feature with no planned development. Staying on Attachments means staying on a dead-end architecture.
Migration involves converting Attachment records to ContentDocument and ContentVersion objects, then linking them to the appropriate records. This can be done through data tools, custom Apex scripts, or third-party utilities. The effort is worth it: once migrated, your documents become searchable, shareable, and manageable through the full Files framework. If your org has large volumes of historical Attachments, prioritize the most active record types first, such as accounts and opportunities, before working through archived data.
Files use the ContentDocument, ContentVersion, and ContentDocumentLink objects in the Salesforce API, while Attachments use the Attachment object. The Files API is significantly more capable, supporting version management, library operations, and cross-record linking through separate, well-structured objects. The Attachment API is simpler but far more limited in what it can do programmatically.
For automation purposes, this matters in several ways. Flow and Apex automations that need to create, update, or route documents should target ContentVersion, not Attachment. You can trigger automations on file uploads, automate version creation, and build document workflow automation that responds to changes in file metadata. The Attachment object doesn’t support this level of integration with modern Salesforce automation tools. If you’re building any kind of automated document process, building on the Files framework is the only viable path forward.
Always use Salesforce Files for any new document workflow. Attachments are a legacy object that Salesforce no longer actively develops, and they lack the storage efficiency, sharing capabilities, and automation support that modern teams need. There is no scenario where starting a new workflow on Attachments is the better choice.
The answer here is straightforward. Whether you’re setting up a contract management process, organizing project files, or building a bulk file upload workflow with drag-and-drop upload functionality, the Files framework is the right foundation. It supports larger file sizes, better metadata management, and connects directly to Salesforce’s automation and collaboration tools. For teams dealing with Salesforce large file upload requirements or needing to upload large files reliably, Files also handles the Salesforce file size limit more gracefully through chunked upload APIs that Attachments never supported.
If you’re setting up document workflows from scratch in 2026, build on Files and don’t look back.
Understanding the difference between Files and Attachments is step one. Actually building a clean, efficient document workflow inside Salesforce is where most teams get stuck. That’s where we come in.
Cartularius is built natively inside Salesforce, which means there’s no switching between platforms and no steep learning curve. It gives your team a familiar, intuitive interface for managing all your Salesforce Files, organized the way your business actually works. Here’s what that looks like in practice:
If your team is ready to move beyond basic file storage and turn Salesforce into a real document management system, explore our plans and see how quickly you can get started.
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