Software Alternatives, Accelerators & Startups

Osaurus VS ForthWrite

Compare Osaurus VS ForthWrite and see what are their differences

Osaurus logo Osaurus

Open source agents that run 100% locally on your Mac

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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Not present
  • 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.

Osaurus

Website
osaurus.ai
Pricing URL
-
$ Details
-
Platforms
-
Release Date
-

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

Osaurus features and specs

  • Native Apple Silicon Optimization
    Osaurus is built specifically for macOS using Apple's MLX framework, allowing it to leverage the Neural Engine and unified memory architecture of M-series chips for faster, more efficient local inference compared to generic cross-platform tools.
  • Local and Private
    Because models run entirely on-device, user prompts and data never leave the machine, offering strong privacy guarantees for sensitive workloads without relying on cloud APIs.
  • Simple Setup and Lightweight Footprint
    As a native macOS app rather than a Docker-based or Electron wrapper, Osaurus tends to install quickly and use fewer system resources than heavier alternatives, making it easy to get started running local LLMs.
  • OpenAI-Compatible API
    Osaurus exposes an OpenAI-style API endpoint, making it straightforward to swap it in as a drop-in replacement for cloud-based LLM calls in existing applications and scripts.
  • No Subscription Costs
    Since inference happens locally on hardware you already own, there are no ongoing API usage fees or subscription costs associated with running models through Osaurus.

Possible disadvantages of Osaurus

  • macOS-Only Availability
    Osaurus is designed exclusively for Apple Silicon Macs, so Windows and Linux users, or those on Intel-based Macs, cannot use the tool at all.
  • Hardware-Dependent Performance
    Inference speed and the size of models you can run are heavily constrained by the amount of unified memory and GPU cores on your specific Mac, meaning older or lower-spec machines may struggle with larger models.
  • Smaller Ecosystem and Community
    Compared to more established tools like Ollama or LM Studio, Osaurus has a newer and smaller user base, which can mean fewer community-contributed guides, integrations, and troubleshooting resources.
  • Limited Model Format Support
    Being tied to the MLX framework, Osaurus may have narrower compatibility with the broad range of model formats (like GGUF) that other local-inference tools support, potentially limiting model choice.
  • Early-Stage Maturity
    As a relatively new project, Osaurus may lack some advanced features, polish, or stability that more mature local LLM runners have developed over a longer period of iteration and user feedback.

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 Osaurus

Overall verdict

  • Osaurus appears to be a lightweight, native on-device LLM runner for Apple Silicon Macs, similar in spirit to tools like Ollama but built with Apple's MLX framework for optimized local inference. For developers and privacy-conscious users who want to run open-source language models locally without cloud dependency, it seems like a solid, efficient choice, though it's a newer/niche tool so ecosystem maturity, model support breadth, and community size are still catching up to more established alternatives.

Why this product is good

  • Runs LLMs entirely on-device, preserving privacy and avoiding API costs
  • Built with Apple's MLX framework, so it's optimized for Apple Silicon performance and efficiency
  • Simple, developer-friendly setup for local inference without cloud dependencies
  • Likely offers an OpenAI-compatible API for easy integration into existing tools/workflows
  • Open-source nature (if applicable) allows transparency and community contributions

Recommended for

  • macOS developers with Apple Silicon (M1/M2/M3) hardware
  • Privacy-focused users who want to avoid sending data to cloud AI providers
  • Hobbyists and engineers experimenting with local/open-source LLMs
  • Teams building offline-first or air-gapped AI applications
  • Users seeking a lightweight alternative to heavier local-inference stacks

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 Osaurus and ForthWrite)
AI
100 100%
0% 0
Email
0 0%
100% 100
Developer Tools
100 100%
0% 0
Email Productivity
0 0%
100% 100

Questions & Answers

As answered by people managing Osaurus 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 Osaurus and ForthWrite

Osaurus Reviews

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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)

What are some alternatives?

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

Ollama - The easiest way to run large language models locally

ReclaimAI - Helps users prioritize their work and personal calendars

opencode - The AI coding agent, built for the terminal.

Superhuman - Superhuman is an email management tool.

Invisibility - One copilot for all AI models on Mac

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