Software Alternatives, Accelerators & Startups

Coefficient.io VS ForthWrite

Compare Coefficient.io VS ForthWrite and see what are their differences

Coefficient.io logo Coefficient.io

Automatically Sync Google Sheets with your Business Systems. No-code reporting and analysis tool.

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.
  • Coefficient.io Landing page
    Landing page //
    2023-10-10

Coefficient is a sidebar app for Google Sheets. Coefficient connects to any data source, imports live data into Google Sheets, automates spreadsheet workflows, and exports data into your business systems.

  • 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.

Coefficient.io

$ Details
-
Platforms
-
Release Date
2019 December

ForthWrite

$ Details
freemium $12 / 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

Coefficient.io features and specs

  • Ease of Integration
    Coefficient.io easily integrates with popular tools like Slack, Google Sheets, and Salesforce, allowing users to pull and push data seamlessly.
  • User-Friendly Interface
    The platform offers an intuitive, user-friendly interface that allows both technical and non-technical users to operate it with ease.
  • Automation Features
    Coefficient.io provides automation capabilities, such as scheduling data pulls and push, which can save significant time and reduce manual efforts.
  • Real-Time Data
    The platform supports real-time data updates, ensuring that users always have access to the most current information.
  • Customization
    Customizable workflows and templates allow users to tailor the platform to their specific business needs.

Possible disadvantages of Coefficient.io

  • Pricing
    Coefficient.io can be expensive for small businesses or startups, especially when scaling up usage.
  • Learning Curve
    Despite its user-friendly design, new users might still face a learning curve to fully utilize all features and capabilities.
  • Limited Offline Access
    The platform's functionality is limited without an internet connection, which can be a drawback in regions with poor connectivity.
  • Customer Support
    Some users have reported that customer support response times can be slow, which can be frustrating when issues arise.
  • Feature Overlap
    There might be overlapping features with other dedicated tools many companies already use, leading to potential inefficiencies.

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 Coefficient.io

Overall verdict

  • Yes, Coefficient.io is generally regarded as a good tool, particularly for businesses looking to enhance efficiency in handling data within spreadsheets. It receives positive reviews for its functionality and ease of use.

Why this product is good

  • Coefficient.io is known for its ability to integrate spreadsheets with business data and automate workflows. It is particularly beneficial for teams that need to streamline data management and analysis processes without extensive coding skills. Users appreciate its user-friendly interface, cost-effectiveness, and the ability to draw insights from data without requiring extensive IT involvement.

Recommended for

    Coefficient.io is recommended for professionals and teams in finance, operations, sales, and any business function that relies heavily on data analysis, reporting, and workflow automation. It's particularly beneficial for small to medium-sized enterprises that need to leverage data effectively without investing heavily in complex IT infrastructure.

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

Category Popularity

0-100% (relative to Coefficient.io and ForthWrite)
Productivity
100 100%
0% 0
Email
0 0%
100% 100
Spreadsheets
100 100%
0% 0
Email Productivity
0 0%
100% 100

Questions & Answers

As answered by people managing Coefficient.io 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 Coefficient.io and ForthWrite. For example, how are they different and which one is better?
Log in or Post with

Reviews

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

Coefficient.io Reviews

We have no reviews of Coefficient.io yet.
Be the first one to post

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, Coefficient.io seems to be more popular. It has been mentiond 4 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.

Coefficient.io mentions (4)

  • Google sheets
    I do this all the time. The problem at first was I didnโ€™t have access to real-time data from my sources. https://coefficient.io/ has a bunch of Google Sheets connectors you can use for free. Since then I never have to update my dashboards, I just send them out. Itโ€™s great. Source: about 4 years ago
  • Ask HN: Who is hiring? (June 2022)
    Coefficient (https://coefficient.io) | Multiple Roles | Fully Remote | Full time | VC-Backed startup Coefficient is a fully remote, seed-stage SaaS startup based in the SF Bay Area. Started by repeat founders with successful past exits, Coefficient has raised $6.7M from Foundation Capital, S28 Capital, and prominent angel investors such as Eric Yuan, Zoom founder/CEO. Coefficient enables users to create custom... - Source: Hacker News / about 4 years ago
  • Ask HN: Who is hiring? (March 2022)
    Coefficient | Multiple Roles | Fully Remote | Full time | VC-Backed startup | https://coefficient.io. - Source: Hacker News / over 4 years ago
  • How to auto fill formula rows?
    Coefficient does that. You can schedule data refreshes, and every time the data updates, it automatically pulls down the formulas for each new row. Source: over 4 years ago

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 Coefficient.io and ForthWrite, you can also consider the following products

Couper.io - couper.io - made by Sevenval

ReclaimAI - Helps users prioritize their work and personal calendars

Grist - Grist makes it easy to transform spreadsheets into a custom database where data is truly actionable.

Superhuman - Superhuman is an email management tool.

Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.

Shortwave - Email smarter & faster with a reinvented experience for your Gmail