LogoFast is one of the most loved free logo tools in the indie-hacker world. Built by Marc Lou, it does one thing with almost no friction: you pick an open-source icon, splash some color on it, rotate it, and download. Grass Lemon comes from the same world (builders shipping side projects fast) but takes the opposite approach: it generates a brand mark with an AI image model and packages the dev assets around it.
If you are an indie maker choosing between them, the decision comes down to one question: do you want a styled icon, or a generated mark?
The 30-second takeaway
| Grass Lemon | LogoFast | |
|---|---|---|
| What you start from | A project description (no icon needed) | A Lucide open-source icon |
| Mark source | AI image model, 6 style presets | Icon library, styled by you |
| Uniqueness | Generated, not selectable by others | Anyone can pick the same icon |
| 16px favicon check | Yes, live preview at 16/32/48/128px | No, single logo download |
| Favicon set + OG + code snippets | Yes | No, logo/icon only |
| BYOK / open-source CLI | Yes, free local workflow | No, browser app (but free, no key) |
| Best for | A real launch where the mark and favicons matter | A 30-second placeholder logo for a side project |
What LogoFast is genuinely great at
LogoFast earns its reputation by removing every ounce of friction. You land on the page, you pick from a large library of clean Lucide icons, you tweak size, rotation, border, fill, and background color, and you download. No account, no paywall, no watermark, no API key. For a developer who just wants something cleaner than the default Next.js favicon on a side project they are shipping this weekend, it is almost perfect.
It also has taste. The Lucide icon set is consistent and modern, and the styling controls are minimal enough that it is hard to make something ugly. Marc Lou's indie-hacker credibility means the tool is trusted and widely recommended.
The honest limitation, which even its Product Hunt reviewers point out, is that it is "a library of open source icons, not logos." You are choosing an icon that anyone else can also choose, and styling it.
What Grass Lemon does differently
Grass Lemon starts from the premise that a real brand mark should be yours, not a stock icon someone else can pick. So instead of an icon library, it takes your project brief and theme colors and generates candidate marks with an image model across six aesthetic directions (geometric, color-blocks, glow, dimensional, tactile, mascot). The output is not a selectable icon; it is a generated mark drawn for your inputs.
That matters most where logos live the longest: the browser tab. Grass Lemon renders every candidate at real favicon sizes (16, 32, 48, 128px) before you commit, because a mark that looks great at 400px can turn to mud at 16px. Then it packages the chosen mark into the set a dev project actually needs: logo variants, a full favicon set (ICO plus PNGs plus Apple touch), an OG image, and framework code snippets (HTML, TanStack, Next, plus a metadata.json).
LogoFast outputs a logo image. Grass Lemon outputs a small launch kit.
The uniqueness question
This is the core trade-off and it is worth stating plainly. LogoFast's icons come from Lucide, an open-source library. If you pick the rocket, the terminal, or the leaf, another founder can pick the same one the same afternoon. That is fine for a prototype. It is less ideal when the logo is meant to identify your product in a browser tab, on Product Hunt, or in an app store listing.
Grass Lemon's marks are generated, so the result is not an icon someone else can select from a menu. You still need to check it is not accidentally close to an existing trademark (true for any generator), but you are not starting from a shared library.
What each one outputs
LogoFast gives you a downloadable styled logo or icon image. That is the scope. There is no favicon .ico, no Apple touch icon, no OG image, no metadata.json, no framework snippets. If you want a favicon from a LogoFast logo, you take the downloaded image to a separate favicon packager.
Grass Lemon's export is wider and code-oriented: logo variants (light, dark, monochrome, source), the favicon set, an OG image, and code snippets ready to paste into a modern web project. It is built for the moment after "I have a logo," which is "now I need it in my repo."
Pricing and workflow
LogoFast is free, full stop. You use it in the browser with no key and no signup. That simplicity is its superpower.
Grass Lemon has a hosted option, but its defining offer is a free, open-source BYOK (bring-your-own-key) skill and CLI. You supply your own image-model key and generate as many marks and kits as you want locally, reading your project theme and writing assets back into your repo. The trade-off is that BYOK means obtaining an API key, which LogoFast never asks for.
When to use which
Use LogoFast if:
- You want a clean logo in 30 seconds for a side project or prototype.
- You are happy picking from an open-source icon library and styling it.
- You do not need favicons, an OG image, or code snippets from the same tool.
- You want zero setup, no key, no account.
Use Grass Lemon if:
- You want a generated mark that is not a stock icon someone else can pick.
- You care whether the mark survives at 16px in a browser tab.
- You want the favicon set, an OG image, and framework snippets in one export.
- You want a free BYOK workflow that fits inside your repo.
A reasonable pipeline is to start with LogoFast when an idea is fresh and you just need something, then move to Grass Lemon when the project is real and the brand has to hold up across a tab, a share card, and an app icon. We are covering more of these tools in the comparison series, and the short version for this pair is: LogoFast for speed, Grass Lemon for a mark you can launch on.
FAQ
Is LogoFast free?
Yes. LogoFast (logofa.st) by Marc Lou is completely free with no account, paywall, or watermark. It is a fast, browser-based tool for styling a logo from an open-source Lucide icon.
Does LogoFast generate favicons and OG images?
No. LogoFast outputs a styled logo or icon image for download. It does not produce a favicon set, an Open Graph image, or framework code snippets. Grass Lemon packages all of those alongside the generated mark.
Are LogoFast logos unique?
Not really. LogoFast is built on the Lucide open-source icon library, so the icon you pick is available to anyone. It is fast and clean, but another project can choose the same icon. Grass Lemon generates a fresh mark with an image model, so the result is not a stock icon someone else can select.
Which is better for a quick side-project logo?
For a throwaway or prototype where you just need a clean icon in 30 seconds, LogoFast is hard to beat: free, instant, no key. For a project you are putting in front of users, where the favicon and logo mark matter and you want code-ready assets, Grass Lemon fits better.
Is Grass Lemon a good LogoFast alternative?
Yes, if you want a distinctive mark rather than a styled library icon, or if you also need favicons, an OG image, and code snippets. If you only want to slap a Lucide icon into a rounded square for free in seconds, LogoFast already does that well.