Pricing

DWS Viewer API is a cloud-based service that integrates with Nutrient Document Engine to support document rendering, processing, and storage in web applications. Pricing is subscription-based, with different tiers depending on your usage needs. You pay monthly or yearly for a specific allocation of viewer sessions, document uploads, storage, and document limits.

What’s the difference between viewer sessions, document uploads, and document limits?

These are three separate metrics that control different aspects of your usage, outlined below.

Monthly viewer sessions

What it is — The number of times users can open and view documents in a given month.

How it works

  • Each time a user loads a document using a session token, it counts as one viewer session
  • A single user viewing the same document multiple times = multiple sessions
  • A single user viewing different documents = multiple sessions
  • Think of it as “document opens” per month

Example — If you have 1,000 monthly viewer sessions, users can open/view documents 1,000 times total during the month, regardless of how many unique documents you have stored.

Document limit

What it is — The maximum number of unique documents you can store in DWS at any given time (not monthly; this is a total storage limit).

How it works

  • This is your document storage capacity, similar to a file cabinet size
  • If your limit is 100 documents, you can have up to 100 unique PDFs/documents stored
  • This limit persists across months; it’s not “100 new documents per month”
  • To add more documents after reaching the limit, you must delete existing ones or upgrade your plan

Example — With a 100-document limit, you could store 100 different PDFs. Users could view these 100 documents thousands of times (limited only by viewer sessions), but you can’t add a new, 101st document without deleting one of the existing 100 first.

Monthly document uploads

What it is — The number of times you can upload or add new documents to DWS per month.

How it works

  • Each API call to upload a document counts as one upload
  • This resets every month
  • Uploading the same document multiple times counts as multiple uploads
  • This is separate from how many documents you can store (document limit)

Example — With 100 monthly uploads, you could:

  • Upload 100 different documents (assuming you don’t exceed your 100-document limit)
  • Upload 50 documents, delete them all, then upload 50 more = 100 uploads used
  • Replace/update documents frequently throughout the month

Viewing multiple documents in a single session

User cannot view multiple documents in a single sessions. This is because each document load creates a new viewer session, even for the same user. Read on for information on how this works.

Scenario 1: Same user, same document, multiple times

  • User opens Document A → 1 session
  • User closes and reopens Document A → 2 sessions
  • User reopens Document A again → 3 sessions

Scenario 2: Same user, different documents

  • User opens Document A → 1 session
  • User opens Document B → 2 sessions
  • User opens Document C → 3 sessions

Key insight: Viewer sessions track usage/activity, while document limit tracks storage capacity. These are independent limits. Your document limit doesn’t restrict which documents can be viewed, e.g. if you have 5,000 documents stored (on a Growth plan), users can view any of them. You’re only limited by your monthly viewer sessions (how many times documents are opened).

Understanding the pricing metrics with real-world examples

This next section will clarify, with concrete scenarios using the Free Plan (1,000 monthly viewer sessions, 100 document limit, 100 monthly uploads).

Example 1: Document library application

You’re building a document library with 50 PDFs stored:

  • Document limit used — 50 out of 100 ✓
  • Monthly uploads used — 50 out of 100 (initial upload) ✓
  • Viewer sessions — Each time any user opens any of these 50 PDFs counts toward your 1,000 monthly viewer sessions
  • Result — 20 users could each view documents 50 times per month (20 × 50 = 1,000 sessions)

Example 2: High-traffic single document

You’re hosting a popular PDF that gets viewed frequently:

  • Document limit used — 1 out of 100 ✓
  • Monthly uploads used — 1 out of 100 ✓
  • Viewer sessions — 1,000 users could each view this document once (1,000 sessions)
  • Problem — You hit your viewer session limit even though you’re only storing one document!

Example 3: Frequently updated documents

You have 25 documents that you update weekly:

  • Document limit used — 25 out of 100 ✓
  • Monthly uploads used — 25 documents × 4 updates = 100 out of 100 ✓
  • Viewer sessions — Independent of uploads; depends on how often users open documents

You hit your upload limit even though you’re only storing 25 documents (because each update = new upload)

Example 4: Document rotation system

You store invoices temporarily and delete old ones:

  • Week 1 — Upload 30 invoices → 30 document limit used, 30 uploads used
  • Week 2 — Delete 30 old invoices, upload 30 new ones → 30 document limit used, 60 uploads used
  • Week 3 — Delete 30, upload 30 new → 30 document limit, 90 uploads used
  • Week 4 — Only 10 uploads remaining for the month

You never exceeded your 100 document limit, but you’re close to your upload limit

What’s included in the free plan?

The Free plan is perfect for development, testing, and small non-commercial projects. It includes:

  • 1,000 monthly viewer sessions (documents opened by users)
  • 100 document limit (total unique documents you can store at once)
  • 500 MiB storage (total file size of all documents)
  • 100 monthly document uploads (API calls to add documents)
  • Full access to viewing, editing, annotations, forms, and electronic signatures
  • HTTPS encryption and secure document storage

Important restriction — Commercial use in enterprises (more than 20 employees OR more than $1 million USD in annual revenue) requires a paid subscription.

What happens when I hit my monthly limits?

When you exceed viewer sessions

  • New document load requests will fail
  • Users will see errors when trying to open documents
  • Existing open sessions may continue to work

Solution — Wait for monthly reset or upgrade your plan

When you hit document limit

  • Upload API calls will be rejected
  • You cannot add new documents until you delete existing ones or upgrade
  • Users can still view existing documents (limited by viewer sessions)
  • This is a total capacity limit, not a monthly limit

Solution — Delete old documents or upgrade your plan

When you exceed monthly uploads

  • Upload API calls will fail for the rest of the billing cycle
  • Users can still view existing documents
  • Resets at the beginning of next billing cycle

Solution — Wait for monthly reset, delete and reupload less frequently, or upgrade

When you hit storage limit (MiB)

  • Cannot upload new documents until you free up space
  • Must delete documents or upgrade

Solution — Delete large files, compress PDFs, or upgrade your plan

Best practice — Monitor your usage in the DWS dashboard and set up alerts before hitting limits.

Do unused sessions/uploads roll over to the next month?

No. Monthly allocations (viewer sessions and document uploads) reset at the beginning of each billing cycle. Unused limits do not carry over.

However, your document limit and storage capacity are ongoing limits, not monthly allocations. If you’re storing 50 documents in January, those same 50 documents still count in February (you don’t get 100 new document slots each month).

Planning tip — If you have variable usage patterns, consider the Custom plan, which offers higher limits, or contact Sales for flexible options.

How do I choose the right plan for my application?

Ask yourself the following questions.

1. How many unique documents will I store?

  • < 100 documents: Free plan may work
  • 100–5,000 documents: Consider Starter
  • 5,000–10,000 documents: Growth plan
  • Greater than 10,000 documents: Contact Sales for Custom plan

2. How often are documents viewed?

  • Low traffic (< 1,000 views/month): Free or Starter
  • Medium traffic (1,000-5,000 views/month): Starter or Growth
  • High traffic (> 5,000 views/month): Growth or Custom

3. How frequently do you upload/update documents?

  • One-time or rare uploads: Lower tier acceptable
  • Weekly updates: Factor in upload limits
  • Daily uploads: May need higher tier or Custom plan

4. What’s your total document storage size?

Calculate total MiB of all documents:

  • Free: 500 MiB (~50 typical PDFs at 10 MB each)
  • Starter: 1,024 MiB (~100 typical PDFs)
  • Growth: 5,120 MiB (~500 typical PDFs)

Pro tip — Start with Free for development, monitor actual usage for 1–2 months in production (with a paid plan), and then optimize your plan based on real data.

Is DWS Viewer API different from DWS Processor API?

Yes, these are separate services with different pricing models. Read on for an overview.

DWS Viewer API (covered in this FAQ)

  • Use case — Document viewing, rendering, and interactive editing in web applications
  • Pricing — Subscription-based (monthly viewer sessions, storage, document limits)
  • Integration — Works with Nutrient Web SDK
  • Storage — Documents are stored and persisted automatically

DWS Processor API

  • Use case — Backend document processing, conversion, generation (document-in, document-out)
  • Pricing — Credit-based (pay per operation, e.g. 0.5 credits for PDF generation, 2 credits for OCR)
  • Integration — HTTP API for server-side workflows
  • Storage — No document storage included
  • Learn more — DWS Processor API documentation

What counts as a viewer session technically?

A viewer session is created when you generate a session token and a user loads a document in the web viewer using that token. Each unique viewing session counts toward your monthly limit.

Implementation details

  • Session tokens are used to authenticate Web SDK clients when connecting to DWS Viewer API.
  • You can configure token settings like expiry date/time and editing permissions.
  • Each NutrientViewer.load() call with a session token creates a new viewer session.
  • Reopening the same document = new session.
  • Learn more — Generate a session token

Code example

// Each load() call = 1 viewer session.
NutrientViewer.load({
  container: "#viewer-container",
  session: "<session_token>", // From DWS API.
});

Can I test the API without a credit card?

Yes! The free plan requires no payment information. Simply sign up and start building immediately with:

  • 1,000 viewer sessions per month
  • 100 documents
  • Full feature access

You can also test capabilities in the API explorer without writing code.

What are my options for uploading documents?

You have two ways to upload documents.

1. Via the dashboard (manual)

  • Upload from the DWS dashboard
  • Get a testing token automatically generated
  • Good for development and testing
  • Counts toward your monthly upload limit

2. Via API (programmatic)

  • Use DWS Viewer API to upload documents directly from your application
  • Obtain an API key from the dashboard (navigate to API keys in the left sidebar)
  • Full control over document management
  • Each API call counts as one upload toward your monthly limit
  • Documentation: Upload documents API

How do I optimize costs when using DWS Viewer API?

Manage document lifecycle efficiently

  • Delete documents that are no longer needed to free up document limit
  • Archive old documents to external storage if not frequently accessed
  • Monitor your document count regularly in the dashboard

Optimize upload patterns

  • Batch document updates rather than uploading frequently
  • Only reupload documents when content actually changes
  • Consider versioning strategy to minimize redundant uploads

Choose the right plan from the start

  • Start with Free for development and early testing
  • Analyze actual usage patterns for 1–2 billing cycles
  • Upgrade to Starter only when ready for commercial use
  • Contact Sales for Custom plan if you have predictable high volume (often better per-unit pricing)

Monitor usage proactively

  • Check DWS Viewer API dashboard regularly
  • Track which documents consume the most viewer sessions
  • Set up alerts before hitting limits
  • Identify usage patterns and optimize accordingly

Consider yearly billing

  • Save 10 percent with annual subscriptions vs. monthly
  • Better for predictable, stable workloads

Can I use DWS Viewer API for a commercial SaaS product?

Yes, but you’ll need a paid subscription if:

  • Your company has more than 20 employees, OR
  • Your company has more than $1 million USD in annual revenue

The Free plan is limited to:

  • Personal projects
  • Open source projects
  • Small businesses under the thresholds above
  • Development and testing environments

Enterprise needs? Contact Sales for custom plans with volume discounts and dedicated support.

What authentication options are available?

DWS Viewer API uses token-based authentication.

Session tokens

  • Used by Web SDK clients to access documents
  • Can be generated via dashboard (for testing) or API (for production)
  • Configurable expiry, permissions, and access controls
  • Each session token creation and use counts as one viewer session
  • Guide: Generate a session token

API keys

  • Used for backend API operations (uploading, deleting, managing documents)
  • Obtain from dashboard under API Keys
  • Keep secure; never expose in client-side code
  • Guide: DWS API authentication

What file size and complexity limits apply?

Limits on file sizes and operation complexity depend on your subscription plan. Specific limits vary by plan tier:

  • Free and Starter plans have standard limits
  • Growth and Custom plans offer higher limits
  • Enterprise Custom plans can be tailored to your needs
  • Storage limits (MiB) are clearly stated for each plan

For specific technical limits (max file size per document, processing time limits, etc.), check your plan details in the dashboard or contact Sales for custom requirements.

What support options are available?

Community support (all plans)

  • Documentation and guides
  • API explorer for testing
  • Code examples
  • Email support
  • Priority response times
  • Technical assistance

Custom plans

  • Dedicated support
  • Custom SLAs
  • Enterprise features
  • Direct access to engineering team

Get help: Contact Support(opens in a new tab)