Software Alternatives, Accelerators & Startups

Zeplin VS ForthWrite

Compare Zeplin VS ForthWrite and see what are their differences

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Zeplin logo Zeplin

Collaboration app for UI designers & frontend developers

ForthWrite logo ForthWrite

Email that sounds like you, and gets measurably more like you every week. Drafts in Gmail, Outlook, and the browser. Free to start.
Visit Website
  • Zeplin Landing page
    Landing page //
    2023-10-19
  • ForthWrite Landing Page
    Landing Page //
    2026-06-19
  • ForthWrite Dashboard
    Dashboard //
    2026-06-19
  • ForthWrite In Gmail
    In Gmail //
    2026-06-19
  • ForthWrite Pricing
    Pricing //
    2026-06-19

ForthWrite is an AI email writing assistant for Gmail and Outlook that learns your writing style from your real sent mail. The more you use it, the more it sounds like you. Get smart drafts in seconds, auto-draft replies before you open your inbox, and maintain your personal voice at scale. Free to start, no credit card required. Works inside Gmail and Outlook on the web.

How it works

ForthWrite captures your tone, sentence rhythm, and sign-offs from your actual sent emails, then uses that profile to generate drafts that match how you write, not a generic AI voice. Every draft you edit or send improves the model over time.

Key features

  • Auto-draft: replies waiting in Gmail before you open your inbox
  • Voice matching from your real sent mail, not templates
  • Recipient-aware drafts that adapt to who you are emailing
  • Prompt Lab for version-controlling and A/B testing your persona prompt
  • BYOK support: bring your own API key for Claude, OpenAI, Grok, Mistral, and more
  • Works in Gmail and Outlook on the web, plus a standalone browser widget
  • Training data export and full data portability

Who uses it

Professionals who send high volumes of relationship-critical email: lawyers, financial advisors, recruiters, account executives, founders, and anyone who wants their inbox handled without sounding like a chatbot wrote it.

Pricing

Free tier includes 10 drafts per week with no credit card required. Paid plans start at $12/month and include unlimited drafts, custom persona prompts, and auto-draft.

ForthWrite

$ Details
freemium $12.0 / Monthly (Standard plan)
Platforms
Web
Release Date
2026 June
Startup details
Country
United States
State
California
City
San Diego
Founder(s)
Curtis Boortz
Employees
1 - 9

Zeplin features and specs

  • Ease of Collaboration
    Zeplin facilitates seamless collaboration between designers and developers by providing a shared space where they can access design specifications, assets, and resources.
  • Design Consistency
    By offering detailed design specifications and exportable assets, Zeplin ensures consistency across different development platforms and helps maintain a unified design system.
  • Automated Asset Export
    Zeplin automatically generates assets in various formats and resolutions, which saves time and reduces the likelihood of errors during the handoff process.
  • Integration with Design Tools
    Zeplin integrates seamlessly with popular design tools like Sketch, Adobe XD, Figma, and Photoshop, making it easy for designers to upload and manage their projects.
  • Version Control
    The platform offers version control for design projects, enabling teams to track changes, revert to previous versions, and ensure they're always working with the most up-to-date designs.

Possible disadvantages of Zeplin

  • Pricing
    Zeplin's subscription model can be costly for smaller teams or individual freelancers, especially when compared to other design handoff tools available in the market.
  • Limited Prototyping Features
    Unlike some other design collaboration tools, Zeplin lacks advanced prototyping features, which might necessitate the use of additional tools for complete design validation.
  • Learning Curve
    New users may require some time to learn Zeplinโ€™s interface and features, which could be a challenge for teams that need to quickly onboard and get up to speed.
  • Dependency on Design Tools
    Zeplin relies heavily on imported designs from other tools rather than allowing for direct design creation within its platform. This dependency could be a limitation for teams looking for an all-in-one solution.
  • Limited Free Tier
    The free version of Zeplin is quite limited in terms of the number of projects and collaborators, which might not be sufficient for larger teams or complex projects.

ForthWrite features and specs

  • Voice Matching
    Learns from your real sent mail, not templates
  • Auto-draft replies
    Replies waiting in Gmail before you open your inbox
  • Batch-drafting
    Draft replies for your entire inbox with one click
  • Works in browser
    Gmail, Outlook, and web browsers
  • BYOK support
    Claude, OpenAI, Grok, Mistral, and more
  • Prompt Lab
    Version control and A/B test your persona prompt
  • Free tier
    10 drafts per week, no credit card required

Analysis of Zeplin

Overall verdict

  • Zeplin is generally considered a good tool, especially for teams seeking better collaboration between designers and developers. Its features are highly appreciated for accuracy and efficiency in implementing design visions. However, its usefulness might depend on specific team needs and workflows.

Why this product is good

  • Zeplin is a popular tool among designers and developers for its ability to bridge the gap between design and development processes. It excels in organizing design files, annotations, and specifications, making it easier for development teams to implement designs accurately. It integrates seamlessly with design tools like Figma, Sketch, and Adobe XD, and provides features like automated design specs, style guides, and assets that streamline the workflow. Its collaborative features allow for efficient communication and feedback loops between team members.

Recommended for

    Zeplin is best suited for designers and developers working in teams where clear design specifications and organized collaboration are critical. It's particularly beneficial for teams using Figma, Sketch, or Adobe XD who want to ensure precise design implementation and reduce misunderstandings between design and development departments.

Zeplin videos

Zeplin Basics: Design Systems

More videos:

  • Demo - Zeplin Demo: What is Zeplin? (Video)

ForthWrite videos

No ForthWrite videos yet. You could help us improve this page by suggesting one.

Add video

Category Popularity

0-100% (relative to Zeplin and ForthWrite)
Design Tools
100 100%
0% 0
Writing Tools
0 0%
100% 100
Prototyping
100 100%
0% 0
Email
0 0%
100% 100

Questions & Answers

As answered by people managing Zeplin and ForthWrite.

Which are the primary technologies used for building your product?

ForthWrite's answer:

Next.js, React, Supabase, Anthropic Claude, OpenAI, Stripe, Vercel, Chrome Extensions API

What makes your product unique?

ForthWrite's answer:

ForthWrite learns your writing style from your actual sent mail, not a generic prompt. Every draft sounds like you wrote it because it was trained on how you actually write. It also auto-drafts replies before you open your inbox, so your email is partially handled before your day starts.

Why should a person choose your product over its competitors?

ForthWrite's answer:

Most AI email tools give you a blank box and a "write for me" button. ForthWrite builds a voice profile from your sent history and gets more accurate with every draft you edit or send. Unlike ChatGPT or Gemini, it works natively inside Gmail and Outlook with no copy-paste. Unlike Lavender, it writes the draft, not just scores it.

How would you describe the primary audience of your product?

ForthWrite's answer:

Professionals who send high volumes of relationship-critical email and cannot afford to sound generic: lawyers, financial advisors, recruiters, account executives, consultants, and founders managing their own inbox.

What's the story behind your product?

ForthWrite's answer:

Built out of frustration with AI writing tools that produce text that sounds nothing like the person sending it, and as a way to handle large amounts of daily email. The core insight was that your sent mail is the best training data you already have, and no tool was using it.

User comments

Share your experience with using Zeplin and ForthWrite. For example, how are they different and which one is better?
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Reviews

These are some of the external sources and on-site user reviews we've used to compare Zeplin and ForthWrite

Zeplin Reviews

Top 5 Zeplin Alternative
As aforementioned, Zeplin suffers some inherent drawbacks that may dent designersโ€™ hopes for faster, easy, and reliable UI design. To avert such scenarios, you donโ€™t have to get stuck with Zeplin as there are numerous other top-notch Zeplin alternatives. The following are some of the top 5 Zeplin alternatives.
Top 6 Figma Alternatives: Prototyping and UI/UX Tools
Zeplin is super affordable. It offers 2 plans: Team, which costs $8.00 per user per month, and Establishment, which costs $16.00 monthly. Zeplin also provides a feature-limited Free Plan and Enterprise Plan.
Source: fronty.com
9 Best InVision Alternatives to Switch to in 2024
Zeplin is a workspace collaboration tool to document what to build and how designs should behave in a central collaborative place for the entire dev team.
Source: designmodo.com
10 Best Adobe XD Alternatives (Free & Paid)
Zeplin is a smart Adobe XD alternative for code lovers. It is a code-based design app where you can source all your components from Storybook, Github, Bitbucket, SourceForge, and other repositories, so they are always code-ready. The app also integrates seamlessly with team collaboration and project management tools like Trello, Proofhub, Monday, Jira, and Slack, offering...
Top 10 Free Adobe XD Alternatives in 2021
One of the top alternatives to Adobe XD is Zeplin, a code-based design tool where your components can be sourced from GitHub, Storybook, and other repositories so they're always code-ready. You can view summaries of your components within your designs and easily see code snippets for how to initialize them. There are also extensive integrations with project management and...

ForthWrite Reviews

  1. curtisboortz
    ยท Founder at ForthWrite ยท
    I built ForthWrite to fix generic AI email, and I still use it every day

    I built ForthWrite because I kept sending emails that sounded like they came from the same generic AI as everyone else. After launching it, I still use it for my own inbox every day, which is about the most honest endorsement I can give.

    The Chrome extension lives inside Gmail and Outlook on the web. Open a thread, hit Alt+Shift+D, and a draft comes back in your voice, not a template. The free tier is real: 10 drafts per week, no API key, no credit card. Voice matching is included on free, because that is the point.

    What keeps it useful compared to Gemini or a chat tab: it learns from what you actually send. Every edit you make before hitting send becomes a signal. Over time the drafts drift closer to how you really write, and the dashboard shows the improvement curve so you can see it happening.

    The web compose surface lets you draft from forthwrite.ai without installing anything, useful for people who want to try before committing to the extension.

    Standard adds recipient-aware and intent-aware drafting plus AI coaching. Pro adds auto-draft (replies waiting when you open Gmail), batch replies, and Prompt Lab for version-controlling your prompts. Teams adds a shared persona and seat-level analytics.

    ForthWrite is not for everyone. If you just need quick replies and tone does not matter, Gemini is free and already in your inbox. ForthWrite is for people where tone does matter: client communication, relationship-driven threads, external correspondence where sounding off costs something real.

    Disclosure: I am the founder and use it daily. Happy to answer questions in the comments.

    ๐Ÿ Competitors: Jace.ai, Fyxer, Mailmeteor
    ๐Ÿ‘ Pros:    Drafts land inside gmail and outlook; no copy-pasting from a chat window|Voice matching is on the free tier, not paywalled behind paid plans|No api key, no credit card to start; free tier runs on a server-side proxy|Learns from every edit you make before sending; drafts improve over time|Full keyboard flow: alt+shift+d to draft in any thread, no mouse required|Byok on paid plans, 9 providers supported, keys encrypted at rest|Web compose at forthwrite.ai works without installing the extension at all
    ๐Ÿ‘Ž Cons:    10 free drafts/week is enough to evaluate, not enough for a heavy inbox|Auto-draft, batch replies, and prompt lab all require the pro tier|Early-stage product; fewer third-party integrations than mature inbox tools|No mobile app: the extension and add-in are desktop-only (chrome on web, or the outlook desktop add-in)

Social recommendations and mentions

Based on our record, Zeplin seems to be more popular. It has been mentiond 23 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.

Zeplin mentions (23)

View more

ForthWrite mentions (0)

We have not tracked any mentions of ForthWrite yet. Tracking of ForthWrite recommendations started around Jun 2026.

What are some alternatives?

When comparing Zeplin and ForthWrite, you can also consider the following products

Invision - Prototyping and collaboration for design teams

Superhuman - Superhuman is an email management tool.

Axure - The most powerful way to plan, prototype and hand off to developers, all without code. Download a free trial and see why professionals choose Axure RP 9.

Gemini - Gemini, formerly known as Bard, is a generative artificial intelligence chatbot developed by Google. Based on the large language model (LLM) of the same name, it was launched in 2023 in response to the rise of OpenAI's ChatGPT.

Balsamiq - Balsamiq. Rapid, effective and fun wireframing software.

Lavender - Realtime coaching for sales emails.