Icon licensing, explained properly

This page covers the licences behind the icons in ICON OOP and what they permit in practice. It is general information written for people who ship things, not legal advice. For anything commercially significant, take proper advice.

The five licences, in plain English

CC0 1.0 (public domain dedication)

The creator has waived their rights as far as the law allows. Effectively public domain. Use it for anything, modify it, sell it, no credit needed. Used by the brand logo collections.

MIT

Do anything you like with it, commercially or not, provided you keep the copyright notice and licence text with the source. The obligation attaches to redistributing the code or files, not to displaying the icons on a website. Used by Tabler, Phosphor and Devicon.

ISC

Functionally equivalent to MIT, just shorter. Same permissions, same notice condition. Used by Lucide.

Apache License 2.0

Permissive like MIT, with two additions. It asks that you state any significant changes you made if you redistribute, and it includes an express patent grant, which is why corporate legal teams tend to be comfortable with it. Used by Material Symbols.

CC-BY 4.0

The only one here with an ongoing visible obligation. You may use it commercially and modify it, but you must credit the creator, link to the licence, and indicate if you made changes. Used by the emoji artwork.

When attribution is actually required

The distinction that trips people up: keeping a licence notice in your source files is not the same as crediting on your website.

A compliant emoji credit is one line, somewhere findable:

Emoji artwork by <a href="https://github.com/jdecked/twemoji">Twemoji</a>,
licensed <a href="https://creativecommons.org/licenses/by/4.0/">CC-BY 4.0</a>.

Footer, about page or credits page is fine. It does not need to sit next to each emoji.

Copyright vs trademark

These protect different things and answer different questions.

So a Simple Icons SVG of a company logo is CC0, meaning copying the file is unrestricted. The logo it draws is still that company's trademark. The licence answers the first question and is silent on the second.

Trademark exists to stop people being misled about who is behind a product. Once you hold that in mind, the rules become intuitive rather than something to memorise.

Using brand logos safely

Referring to a company by its mark is generally permitted, in most jurisdictions, under nominative fair use: you may use a trademark to identify the trademark owner's product, provided you use no more than necessary and do not suggest sponsorship or endorsement.

Normally fine:

• Social icons linking to your own profiles.
• "Integrates with Stripe", with the mark beside the name.
• Payment method marks at checkout.
• A tech stack list on a developer portfolio.
• Comparison and review content.
• Internal slides and diagrams.

Causes problems:

• Customer logo walls where they are not customers.
• Merchandise carrying someone else's mark.
• Using a mark, or something close to it, as your own logo, app icon or favicon.
• Altering a logo: recolouring, stretching, or combining it with yours into one lockup.
• Placing a mark in a context the brand would object to.

The test in one sentence: if the logo describes something true about your product, you are almost certainly fine; if the logo is doing work for your brand, you are not. More in brand logos.

Client work and agencies

Common questions, short answers.

Can I use these icons in a site I build for a client? Yes. Permissive licences do not distinguish between using something yourself and using it in work you are paid for.

Can I charge the client for the site? Yes. You are charging for your work, not selling the icons.

Do I need to tell the client? Not legally, but it is good practice, and it matters if the project uses emoji, because the attribution obligation then lands on their site and should not be a surprise.

What if the client rebrands and recolours the icons? Fine for UI icons under all these licences. Not fine for brand logos belonging to other companies.

What should I hand over? A short licences file listing each set, its licence and a link. Ten minutes of work that prevents an awkward conversation two years later when someone asks where the icons came from.

What you cannot do

• Sell the icons as icons. Repackaging a free set and selling it as your own icon pack is against the spirit of every licence here and, for the notice-requiring ones, against the letter too.
• Claim authorship. You did not draw them.
• Register them as your trademark. An icon in wide public use cannot function as a distinctive mark, and attempting it is likely to fail and be expensive.
• Strip licence notices when redistributing files. This is the one condition MIT, ISC and Apache actually impose.
• Use emoji without credit. The one visible obligation on this site.

Using icons inside a product you sell is not resale and is explicitly permitted. The distinction is whether the icons are the product.

A practical checklist

1. Note which set each icon came from, ideally in a single file in your repo.
2. If you used emoji, add the credit line before launch.
3. If you ship a desktop or mobile app, include an open source licences screen.
4. For brand logos, check the company's own brand guidelines, which most large companies publish.
5. Never alter a brand logo's colours or proportions.
6. Keep the licence files if you commit the icon source into your repository.
7. If a use is commercially significant and looks marginal, get advice rather than guessing.

Frequently asked questions