Software Alternatives, Accelerators & Startups

RegExr VS ForthWrite

Compare RegExr VS ForthWrite and see what are their differences

RegExr logo RegExr

RegExr.com is an online tool to learn, build, and test Regular Expressions.

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
  • RegExr Landing page
    Landing page //
    2023-07-28
  • 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.

RegExr

Website
regexr.com
Pricing URL
-
$ Details
Platforms
-
Release Date
-
Startup details
Country
United States

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

RegExr features and specs

  • User-Friendly Interface
    RegExr offers an intuitive and visually appealing interface that makes it easy for users to write, test, and understand regular expressions.
  • Real-time Feedback
    Changes to the regular expression and input text are reflected immediately, allowing users to see the effects of their adjustments in real-time.
  • Built-in Cheatsheet
    RegExr includes a handy cheatsheet that provides quick access to common regex patterns and syntax, making it easier for users to learn and reference rules.
  • Community Examples
    Users can explore and share community-generated regex patterns, which can serve as valuable examples or starting points for creating their own regex.
  • Detailed Explanation
    Each part of the regex pattern can be hovered over to display detailed tooltips explaining its function, aiding in the understanding of complex expressions.
  • Cross-Platform Accessibility
    As a web-based tool, RegExr can be accessed from any modern browser without the need for installation, making it convenient to use on multiple devices.

Possible disadvantages of RegExr

  • Limited Offline Use
    Since RegExr is a web-based application, it requires an internet connection, limiting its utility for users who need to work offline.
  • Learning Curve
    While the tool is user-friendly, users still need to have a foundational understanding of regular expressions to use RegExr effectively.
  • Performance Issues
    For extremely large inputs or very complex regular expressions, the tool may experience performance lags or slowdowns.
  • Limited Advanced Features
    RegExr may lack some advanced features found in more specialized or professional regex tools, such as integration with development environments or extensive scripting capabilities.
  • Privacy Concerns
    Users inputting sensitive data need to be cautious, as the web-based nature of the tool could raise privacy or data security concerns.

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 RegExr

Overall verdict

  • RegExr is widely regarded as an excellent tool for working with regular expressions due to its comprehensive feature set and ease of use.

Why this product is good

  • RegExr is considered a good tool for learning, creating, testing, and sharing regular expressions (regex). It offers a user-friendly interface, extensive documentation, real-time regex parsing, highlighting, and explanations, making it accessible for both beginners and experienced users. The platform provides a library of community-contributed patterns and a robust set of tools that helps users understand and construct regex patterns effectively.

Recommended for

  • Beginners learning regular expressions.
  • Developers needing to test and refine regex patterns.
  • Educators teaching regex concepts.
  • Anyone requiring an intuitive interface to work with regular expressions.

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 RegExr and ForthWrite)
Programming Tools
100 100%
0% 0
Email
0 0%
100% 100
Regular Expressions
100 100%
0% 0
Email Productivity
0 0%
100% 100

Questions & Answers

As answered by people managing RegExr 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 RegExr 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 RegExr and ForthWrite

RegExr Reviews

We have no reviews of RegExr 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, RegExr seems to be more popular. It has been mentiond 368 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.

RegExr mentions (368)

  • Learning Perl - Regular Expressions
    Use Online Tools: There are many online regex testers and visualizers that can help you see how your patterns match against sample text. These tools often provide explanations for each part of the regex. I personally use https://regexr.com/. - Source: dev.to / about 1 year ago
  • The importance of the environment in Regex pattern matching
    However - here it becomes weird - when testing the original regex rule (the first one, without the \u00A0 part) on the same string in an interactive visualiser (https://regexr.com/ for instance), there is a match:. - Source: dev.to / almost 2 years ago
  • Ask HN: How did you learn Regex?
    Learned regex in the 90's from the Perl documentation, or possibly one of the oreilly perl references. That was a time where printed language references were more convenient than searching the internet. Perl still includes a shell component for accessing it's documentation, that was invaluable in those ancient times. Perl's regex documentation is rather fantastic. `perldoc perlre` from your terminal. Or... - Source: Hacker News / almost 2 years ago
  • Ask HN: How did you learn Regex?
    I read a lot on https://www.regular-expressions.info and experimented on https://rubular.com since I was also learning Ruby at the time. https://regexr.com is another good tool that breaks down your regex and matches. One of the things I remember being difficult at the beginning was the subtle differences between implementations, like `^` meaning "beginning of line" in Ruby (and others) but meaning "beginning of... - Source: Hacker News / almost 2 years ago
  • Ask HN: How did you learn Regex?
    Mostly building things that needed complex RegEx, and debugging my regular expressions with https://regexr.com/. - Source: Hacker News / almost 2 years ago
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 RegExr and ForthWrite, you can also consider the following products

regular expressions 101 - Extensive regex tester and debugger with highlighting for PHP, PCRE, Python and JavaScript.

ReclaimAI - Helps users prioritize their work and personal calendars

rubular - A ruby based regular expression editor

Superhuman - Superhuman is an email management tool.

Expresso - The award-winning Expresso editor is equally suitable as a teaching tool for the beginning user of regular expressions or as a full-featured development environment for the experienced programmer with an extensive knowledge of regular expressions.

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