Introducing our AI app builder
Assembly

Assembly vs. Karbon

Updated November, 2025

Try Assembly for free

While both Assembly and Karbon help accountants manage their clients, Assembly has a superior client portal experience, more flexible file sharing models and automations, and better project management features. If you’re looking for a seamless, branded client experience, Assembly is the better choice.

  • Assembly has a superior branded client portal experience
  • Assembly has task management & collaboration beyond email
  • Assembly has a flexible secure file sharing model
  • Assembly has automation depth with 3rd party integrations

What do customers say?

While Karbon offers more accounting-specific practice management workflows, users rate Assembly's client portal experience higher.

See the full comparison on G2

Capterra score

Assembly
4.8/5
Karbon
4.7/5

Ease of Admin

Assembly
9.4/10
Karbon
8.2/10

Ease of Use

Assembly
9.4/10
Karbon
8.8/10

Ease of Setup

Assembly
9.4/10
Karbon
7.9/10

Quality of Support

Assembly
9.5/10
Karbon
9.4/10

Assembly gives clients a branded, secure, all-in-one workspace

Assembly was designed for firms that care about client experience. Each client gets a white-label portal for messaging, document sharing, e-signatures, and payments—all with your firm’s branding. Karbon focuses more on internal collaboration and offers limited visibility to clients, requiring firms to juggle separate tools for communication, file sharing, and billing.

  • Secure document requests

    Assembly
    Karbon

  • Role-based permissions

    Assembly
    Karbon

  • White-label client portal

    Assembly
    Karbon

  • Real time chat for clients

    Assembly
    Karbon

  • Branded client-facing file storage hub

    Assembly
    Karbon

  • Progress and visibility tracking

    Assembly

    Clients see tasks, statuses and progress

    Karbon

    Clients view assigned tasks, but less full transparency into workflow

  • Self-serve payment links

    Assembly

    Branded invoices + one-click payment links and subscriptions.

    Karbon

    Full billing engine, but more complex setup and fewer self-serve payment links.

Assembly automates client workflows with deeper integrations.

Assembly connects your client operations end-to-end through powerful integrations and workflow automations. From onboarding and billing to reminders and document approvals, everything runs in one place. In contrast, Karbon’s automation is limited to internal task triggers and email workflows, with fewer client-facing automation options or open API capabilities.

  • Workflow automations

    Assembly
    Karbon

  • Task templates & reminders

    Assembly
    Karbon

  • Client reminder automations

    Assembly
    Karbon

  • eSignature automation

    Assembly
    Karbon

  • Custom data sync support

    Assembly
    Karbon

  • Automated client onboarding

    Assembly

    Unified portal, forms, contracts, billing + full automation.

    Karbon

    Handles internal task workflows, not full external client-onboarding.

  • API & Webhooks

    Assembly

    Full REST API + native webhooks for many events.

    Karbon

    API present; webhooks available but fewer built‐in event types.

  • Multi-system integrations (Airtable, Calendly, ClickUp)

    Assembly

    Plug-and-play integrations-easy setup for non-tech users.

    Karbon

    Integrations available but fewer external-tool links-more setup required

Assembly delivers secure, structured file sharing built for client collaboration

Assembly offers a flexible file-sharing model with structured folders, secure document requests, instant notifications, and in-app previews, making external collaboration seamless without relying on email attachments. Clients get magic-link access with low login friction and can upload, view, and organize files in a branded, mobile-friendly interface. Karbon focuses primarily on internal file storage with limited client-facing file-sharing capabilities.

  • Structured folder organization

    Assembly
    Karbon

  • Secure document requests

    Assembly
    Karbon

  • Magic-link file access

    Assembly
    Karbon

  • In-app file previews

    Assembly

    Instant document previews without downloads—faster client review and approval

    Karbon

    Limited

  • Email + in-app notifications

    Assembly

    Dual-channel notifications keep clients informed without inbox overload

    Karbon

    Email-focused

  • Mobile-optimized file uploads

    Assembly

    Fully optimized for mobile browser access

    Karbon

    Basic mobile support

  • Client-facing file hub

    Assembly

    Branded secure portal with instant client access

    Karbon

    Internal-focused storage with minimal client interface

Assembly enables true client collaboration with visible, actionable task management

Assembly goes beyond internal task tracking by giving clients visibility into their tasks, threaded comments for collaboration, and automated reminders, reducing email back-and-forth and keeping projects moving. Task templates and checklists ensure consistency across client engagements, while clients can see real-time progress and next steps. Karbon excels at internal team workflows but offers limited client-facing task visibility and collaboration features.

  • Task templates & checklists

    Assembly
    Karbon

  • Internal task assignment

    Assembly
    Karbon

  • Automated task reminders

    Assembly
    Karbon

  • Client-visible tasks

    Assembly

    Full task transparency keeps clients informed and engaged in real-time

    Karbon

    Limited visibility

  • Threaded task comments

    Assembly

    Client-visible threaded discussions reduce email chains and keep context in one place

    Karbon

    Internal comments only

  • Client task collaboration

    Assembly

    Clients can view, comment, and act on tasks directly in portal

    Karbon

    Tasks primarily managed internally; clients have minimal interaction

  • Email-triggered task creation

    Assembly

    Via Zapier/Make integrations and API

    Karbon

    Native email-to-task workflows

See all comparisons

Your clients deserve better than Karbon

Try Assembly for free, no credit card required.

Get startedBook a demo