Software Alternatives, Accelerators & Startups

Humanloop VS ForthWrite

Compare Humanloop VS ForthWrite and see what are their differences

Humanloop logo Humanloop

Train state-of-the-art language AI in the browser

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
  • Humanloop Landing page
    Landing page //
    2023-08-23
  • 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

Humanloop features and specs

  • Ease of Use
    Humanloop is designed to be user-friendly, making it easier for users with varying levels of technical expertise to create and manage machine learning models.
  • Interactivity
    The platform provides an interactive environment where users can iteratively improve their models by integrating human feedback, leading to better performance.
  • Time Savings
    By facilitating faster model iteration and immediate feedback, Humanloop helps save significant time in the machine learning development cycle.
  • Integration Capabilities
    Humanloop offers robust integration options with various tools and platforms, helping users streamline their workflows.
  • Improved Model Accuracy
    The platform allows for continuous model improvement through active learning and human-in-the-loop approaches, enhancing model accuracy over time.

Possible disadvantages of Humanloop

  • Cost
    Depending on the subscription or usage level, Humanloop may become expensive, particularly for small teams or individual developers.
  • Learning Curve
    Despite its user-friendly design, there can still be a learning curve for users new to machine learning or human-in-the-loop systems.
  • Dependence on Human Feedback
    The effectiveness of Humanloop relies heavily on the quality and consistency of human feedback, which can introduce variability and potential biases.
  • Data Privacy Concerns
    Handling and sharing data with a third-party platform may raise privacy and compliance concerns, particularly for sensitive information.
  • Limited Offline Functionality
    Humanloop's cloud-based nature means that its functionalities are limited or inaccessible without an internet connection.

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 Humanloop

Overall verdict

  • Humanloop is considered a strong choice for organizations seeking to enhance their AI model development process through interactive learning and feedback integration. Its user-friendly interface and powerful features make it a valuable tool in the AI development landscape.

Why this product is good

  • Humanloop, an AI and machine learning platform, is highly regarded for its ability to effectively integrate human feedback into AI systems. It's particularly praised for enhancing model accuracy and improving user experience by allowing for seamless annotation and model training. The platform offers tools that facilitate collaboration between developers and non-technical domain experts, making it easier to refine AI models effectively.

Recommended for

  • AI developers looking to improve model performance through human feedback.
  • Teams seeking a collaborative environment to refine AI processes.
  • Companies that need an accessible tool for both technical and non-technical staff.

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

Humanloop videos

Train and deploy NLP โ€” Humanloop

More videos:

  • Review - The Great AI Implementation with Raza Habib of Humanloop

ForthWrite videos

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

Add video

Category Popularity

0-100% (relative to Humanloop and ForthWrite)
AI
92 92%
8% 8
Writing Tools
0 0%
100% 100
Developer Tools
100 100%
0% 0
Email
0 0%
100% 100

Questions & Answers

As answered by people managing Humanloop 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 Humanloop 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 Humanloop and ForthWrite

Humanloop Reviews

We have no reviews of Humanloop 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, Humanloop seems to be more popular. It has been mentiond 5 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.

Humanloop mentions (5)

  • Ask HN: Who is hiring? (December 2024)
    Humanloop | London and San Francisco | Full time in person | https://humanloop.com Humanloop is building infrastructure for AI application development. We're the LLM Evals Platform for Enterprises. Duolingo, Gusto, and Vanta use Humanloop to evaluate, monitor, and improve their AI systems. ROLES:. - Source: Hacker News / over 1 year ago
  • Show HN: PromptDoggy โ€“ Prompt Management for Product and Engineering Teams
    - https://humanloop.com/) for teaching me the philosophy of implementing a copilot textarea. I wish I could have used the project directly, but integrating just one React component into Rails while keeping importmap and StimulusJS was quite challenging. Given the limited time, I decided to move on with StimulusJS. This is our first time building an open-source project to share with the world, and weโ€™re a bit... - Source: Hacker News / almost 2 years ago
  • How are generative AI companies monitoring their systems in production?
    - Conversational simulation is an emerging idea building on top of model-graded evalโ€ - AI Startup Founder Things to consider when comparing options: โ€œTypes of metrics supported (only NLP metrics, model-graded evals, or both), level of customizability; supports component eval (i.e. Single prompts) or pipeline evals (i.e. Testing the entire pipeline, all the way from retrieval to post-processing)โ€ โ€œ+method of... - Source: Hacker News / almost 3 years ago
  • Ask HN: Who is hiring? (March 2023)
    Humanloop (YC S20) | London (or remote) | https://humanloop.com We're looking for exceptional engineers that can work at varying levels of the stack (frontend, backend, infra), who are customer obsessed and thoughtful about product (we think you have to be -- our customers are "living in the future" and we're building what's needed). Our stack is primarily Typescript, Python, GPT-3. Please apply at... - Source: Hacker News / over 3 years ago
  • Compiling a list of tools for building LLM apps
    https://humanloop.com/ Find the prompts users love and fine-tune custom models for higher performance at lower cost. - Source: Hacker News / over 3 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 Humanloop and ForthWrite, you can also consider the following products

Langfuse - Langfuse is an open-source LLM engineering platform that helps teams collaboratively debug, analyze, and iterate on their LLM applications.

Superhuman - Superhuman is an email management tool.

Hugging Face - The AI community building the future. The platform where the machine learning community collaborates on models, datasets, and applications.

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.

LangChain - Framework for building applications with LLMs through composability

Lavender - Realtime coaching for sales emails.