Software Alternatives, Accelerators & Startups

Polypane VS ForthWrite

Compare Polypane VS ForthWrite and see what are their differences

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Polypane logo Polypane

The browser for ambitious web developers that want to 5ร— their quality and efficiency.

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.
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  • Polypane Landing page
    Landing page //
    2021-08-04

Developing and designing just got easier. The most powerful browser for web developers. Available on all platforms.

Polypane shows your site in multiple viewports at once and keeps them all in sync while you work.

Develop responsive websites and apps twice as fast and get better results, because you wont be skipping screen sizes and wishing for the best.

Build higher quality websites, whether you use Wordpress, React, Angular, Svelte, Bootstrap, Drupal or any other CMS, library or framework.

Polypane has the right tools built-in for developing, debugging and testing, like devtools extensions, live reloading, accessibility testing and more.

  • 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.

Polypane

$ Details
paid Free Trial $9.0 / Monthly (Individual user)
Platforms
Windows Mac OSX Linux Chrome OS
Release Date
2019 May

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

Polypane features and specs

  • Multi-View Testing
    Polypane allows developers to view and test their website in multiple screen sizes simultaneously, making responsive design testing more efficient.
  • Live Reloading
    The application supports live reloading, which means any changes made to the code are instantly reflected in the preview panes without needing to refresh manually.
  • Developer Tools Integration
    Polypane integrates seamlessly with common developer tools and frameworks, enhancing the workflow for developers who use tools like React, Vue, and Angular.
  • Accessibility Checks
    Built-in accessibility tools help ensure that web pages comply with accessibility standards, making it easier to identify and fix issues.
  • Performance Insights
    The software provides performance metrics and recommendations, aiding developers in optimizing load times and overall performance.
  • Collaboration Features
    Polypane includes features designed for team collaboration, such as the ability to share previews and feedback with team members.
  • Dark Mode
    A dark mode option is available, offering a more comfortable viewing experience for developers who prefer it or work in low-light conditions.
  • Customizable Layouts
    Users can customize the layout of the panes to better suit their workflow, offering a flexible user experience.

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 Polypane

Overall verdict

  • Yes, Polypane is an excellent tool, especially for professionals who need precise control over design and responsiveness testing. It can significantly streamline the process of developing and testing web applications, making it a worthwhile investment for serious developers.

Why this product is good

  • Polypane is highly regarded for its robust feature set tailored for web developers and designers. Its standout features include synchronized browsing across customizable viewports, detailed accessibility testing, and live reloading. Polypaneโ€™s focus on responsive design and accessibility makes it a comprehensive tool for developing web pages that look and perform well across different devices and meet modern web standards.

Recommended for

    Polypane is particularly recommended for web developers, front-end developers, UX/UI designers, and accessibility specialists who require an integrated environment for testing different screen sizes, resolutions, and accessibility features in a cohesive manner.

Analysis of ForthWrite

Overall verdict

  • I don't have verified information about a product called ForthWrite (forthwrite.ai). I cannot confirm its features, quality, or reputation, so I'm unable to provide an accurate assessment of whether it's good.

Why this product is good

  • No reliable data available on this specific product in my knowledge base
  • This may be a newer product, a niche tool, or possibly a fictional/hypothetical name
  • Providing details without verified information could result in inaccurate or fabricated claims

Recommended for

  • Unable to determine without verified product information
  • Consider checking the official website, user reviews on platforms like G2 or Trustpilot, and independent tech review sites for accurate details

Polypane videos

Polypanel Competition Results!

More videos:

  • Demo - Polypane Demo

ForthWrite videos

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

Add video

Category Popularity

0-100% (relative to Polypane and ForthWrite)
Developer Tools
100 100%
0% 0
Writing Tools
0 0%
100% 100
Design Tools
100 100%
0% 0
Email
0 0%
100% 100

Questions & Answers

As answered by people managing Polypane 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

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Reviews

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

Polypane Reviews

We have no reviews of Polypane yet.
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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, Polypane seems to be more popular. It has been mentiond 40 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.

Polypane mentions (40)

  • Experimenting with Random() in CSS
    The point isn't showing what they look like, it's that the result is randomized. Screenshots aren't, so that kind of defeats the purpose. The article starts with instructions on how to actually see and interact with the demos (the easiest is to use [Polypane](https://polypane.app)), as well as a video showing all the demos from the article running in Polypane. - Source: Hacker News / 23 days ago
  • ๐Ÿšช Donโ€™t Lock Users Out: A Practical Guide to Accessibility for Devs
    We also need to talk about Source Order vs. Tab Orderโ€”theyโ€™re more different than youโ€™d expect ๐Ÿ‘€. Source Order is the sequence of nxodes inside their parent in the DOM. Tab Order is the sequence of focusable nodes navigated using the Tab key. If a focusable element lacks tabindex, it follows a depth-first traversal of Source Order (visualized conceptually as a traversal path). Want to visualize Source Order?... - Source: dev.to / about 1 year ago
  • 22 Unique Developer Resources You Should Explore
    URL: https://polypane.app What it does: A browser tailored for developers, enabling real-time testing and previewing of responsive designs. Why it's great: Test your site on multiple screen sizes simultaneously for smoother cross-device optimization. - Source: dev.to / over 1 year ago
  • Show HN: Linkpreview, see how your sites looks in social media and chat apps
    That's pretty cool! Get ready to keep these up to date monthly or become obsolete quickly. One of the downsides of tools like this is that your URL needs to be available online so if there's an issue, your iteration loop is quite long. In Polypane [1] I've built social media previews that work with any local URL but also let you overwrite that URL for the social media that display those. I built (and frequently... - Source: Hacker News / almost 2 years ago
  • Polypane 20: Browser features and performance
    The address bar in Polypane can match URLs and page titles based on fragments. So you can type po blo 20 to get to e.g. https://polypane.app/blog/polypane-20-browser-features-and-performance/. - Source: dev.to / about 2 years ago
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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 Polypane and ForthWrite, you can also consider the following products

Responsively - Develop responsive web-apps 5x faster!

Superhuman - Superhuman is an email management tool.

Sizzy - The browser for designers and developers

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.

LT Browser by Lambdatest - LT Browser is a free dev friendly browser for developers and testers. You can see mobile view of website on different screen sizes and resolution on 50+ pre installed view ports. You can build, test and debug your website faster then ever.

Lavender - Realtime coaching for sales emails.