What a charting library licence allows

A charting library is the one part of a trading screen that looks free, and several of them are. What is usually missed is that "free" is an answer about the code, and a price chart has two owners: whoever wrote the renderer and whoever produced the prices. This page reads the licence texts of the libraries in this catalogue, says what each one actually asks of you, and then walks the second licence that none of them can give you.

How it works

A charting library takes arrays of timestamps and numbers and turns them into candles, lines and axes in the browser. Out of the box, none of the libraries here fetches prices. Everything it draws comes from a feed you connect — TradingView says as much on its own library page, where the libraries are the components "you host on your servers, and connect your data to them through the API".

So a financial chart on a public page rests on two separate permissions:

• The code licence, from the library's author. It says whether you may ship the renderer, to whom, with what notice, and whether you pay. This is the part the library's pricing page is about.
• The data licence, from the exchange or the vendor you buy prices from. It says whether you may show those numbers to other people, how fresh, and what each viewer costs. No library in this category sells it.

The code licences in this category come in five shapes, and every library here fits one of them:

1. Permissive open source — Apache-2.0 or MIT. Use it anywhere, commercially, and carry a notice. Apache ECharts, Plotly.js and KLineChart.
2. Permissive with a condition added — Lightweight Charts, which is Apache-2.0 plus a requirement from TradingView to credit it and link to its site.
3. Free under a contract — TradingView Advanced Charts. No fee, no source code, and an agreement with eligibility rules, marketing obligations and damages.
4. Free with branding, paid without it — amCharts, whose free build is usable commercially as long as its link stays on the chart.
5. Commercial, with a narrow free tier — Highcharts Stock, AnyStock and SciChart.js, free only for non-commercial, educational or evaluation use and sold per seat, per product or per domain above that.

The permissive licences ask for a notice

Apache-2.0 and MIT both let you use, modify and redistribute the library in a commercial, closed-source product without paying anyone. What they ask in return is small and easy to miss in a bundler.

MIT asks for one thing. The Plotly.js licence file says "the above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software." A minified bundle served to every visitor is a copy, so the notice has to survive the build — in the bundle, or in a licences file shipped beside it.

Apache-2.0 asks for a little more, in section 4 of the licence. When you redistribute the work you must give recipients a copy of the licence, mark files you changed, and keep the original copyright and attribution notices. Clause 4(d) is the one that reaches a front end: if the work ships a NOTICE file, a Derivative Work you distribute must include a readable copy of its attribution notices — in a NOTICE file of your own, in your source or documentation, or "within a display generated by the Derivative Works, if and wherever such third-party notices normally appear". An about page or a licences screen is where most products put them.

The notices themselves are short. Apache ECharts' NOTICE is a few lines crediting The Apache Software Foundation. KLineChart's credits two parties — itself and TradingView, whose Lightweight Charts licence the package also carries — so shipping it means shipping a TradingView attribution even though you never installed a TradingView package.

Two limits of these licences matter more than the notices. Apache-2.0 grants no trademark rights: section 6 permits the licensor's names only as needed to describe where the work came from and to reproduce the NOTICE, so you may ship ECharts but not brand your product with its name. And neither licence gives you anything else: no support, no warranty, and — the subject of the second half of this page — no data. Neither Apache ECharts nor Plotly.js has a paid edition of the library to buy instead.

Lightweight Charts: Apache-2.0 and a link

Lightweight Charts is the only TradingView library anyone may use — companies, individuals, open-source projects, hobby dashboards. The licence file is Apache-2.0 verbatim. The repository's README then adds a paragraph of its own: "This license requires specifying TradingView as the product creator. You shall add the 'attribution notice' from the NOTICE file and a link to https://www.tradingview.com/ to the page of your website or mobile application that is available to your users."

That is two obligations, not one:

• The NOTICE text — "TradingView Lightweight Charts™" and a TradingView copyright line — which is what Apache-2.0 clause 4(d) asks for anyway.
• A link to tradingview.com on a page your users can reach. This part is TradingView's, and it is the part people drop.

The README also gives the cheap way to meet the second: the chart's attributionLogo layout option draws a TradingView link on the chart itself, and the README says it "will satisfy the link requirement". The Lightweight Charts card records that the option is on by default. Turning it off to tidy a design is fine only if the link then appears somewhere else a user can reach.

The three documents in the repository do not say the same thing, and the difference is exactly the link. The LICENSE file is the Apache-2.0 text, unchanged; it asks for the NOTICE lines and says nothing about a link, and its clause 4(d) adds that the contents of a NOTICE file "do not modify the License". The NOTICE file holds the product name and a copyright line, and no link. The link appears only in the README's License section, which says the licence "requires" it and uses "shall"; the next sentence of the same README moves to a request, saying TradingView would be "grateful" for a prominent placement.

So a reader has three documents and two ways to reconcile them. One is to meet the README, which with attributionLogo left on costs nothing. The other, for a design that cannot carry the link, is to put the question to TradingView in writing before shipping: whether the link is a condition of use or a request, and whether a link on a credits page meets it.

Advanced Charts: free, under a contract

Advanced Charts, formerly the Charting Library, is the chart most traders recognise, and TradingView does not charge for it. It is not open source and it is not available to everyone. The library page says TradingView does not provide it "for personal use, hobbies, studies, or testing" and that the licences "are only available to companies for use in public web projects". You apply, and if approved you sign the Free Advanced Charts Agreement. The version read for this page carries the stamp v.0626.FAC and no printed date.

What the agreement allows, clause by clause:

• 2.2 — you host the library and "integrate the Client's own Market Data feed streaming and history". It brings no data.
• 2.4 — the licence is for a public access service "as a free offering only, and whether account registration is required or not", and "not for private, personal or internal uses". A paid product, an internal desk tool and a personal project are all outside it. TradingView also gets free, unlimited access to whatever you build, to check compliance.
• 2.5 — the library may not sit in any public code repository, and a project using it may not be open source in a way that exposes the library code.
• 2.6(k) — you may not publish "any analysis or benchmarking" of the services or their performance.
• 2.11 and 3.2 — the price, paid in marketing. You carry TradingView branding with a link to its site, "without any nofollow, ugc, or sponsored link attributes", and you publish a blog post or news article announcing the partnership, or another placement TradingView approves with a contextual backlink.
• 4.2(b) — either side may end the agreement on sixty days' written notice.
• 7.5 — the one dollar figure in the document: once a breach goes uncured for ten days after notice, TradingView may seek liquidated damages of 50,000 dollars "for each and every proven breach".
• 10 — market data compliance is yours: you secure "appropriate licensing from relevant domestic exchanges or third-party providers", and TradingView "bears no responsibility".

Read together, that is a licence for one shape of product: a free, public, closed-source website of a company willing to announce the relationship. A subscription analytics product, an open-source terminal and an in-house blotter do not fit it, and for those the choice in TradingView's range is Lightweight Charts or Trading Platform, a separate product with its own application and, per the Advanced Charts card, a price you ask for.

Commercial licences sell the same four answers

The commercial libraries look as if each invented its own price list. Read side by side, they are asking the same four questions, and the answers set the tier.

Is it for money? The free tiers here are drawn narrowly around not being commercial. The Highcharts End-User License Agreement, version 1.0 of 20 January 2026, grants free use only for Personal Use — "a natural person for purposes that are entirely non-commercial, non-professional" — and Educational Use at an accredited institution. It spells out that a commercial licence is needed for "any use in an internal business operational context, such as for prototyping, research and development, or internal presentations". A startup's demo is commercial on the first day. SciChart.js's free Community edition, per its card, is non-commercial apart from a limited evaluation period, and draws a watermark it will not let you hide.

Is it behind a login? This is the line most people do not expect. On their cards, amCharts's cheapest paid seat covers public sites with no login and the next tier up covers applications behind one; AnyStock's Website licence is void the moment the site requires a login; Highcharts separates a SaaS licence for a public application from an Internal one.

Is it inside your company or in front of customers? Highcharts' Internal licence, for intranets and internal apps only, is about half the price of its SaaS one; AnyStock sells an Internal licence for applications behind the firewall as a tier of its own.

Do you ship it inside software someone else installs or hosts? That is OEM or its equivalent, a separate and dearer licence at all four vendors, and at Highcharts and AnyStock a price you can only get by asking.

amCharts is the outlier worth knowing. Its licence file calls the terms "linkware" and says you can "use amCharts software in any of your projects, including commercial", provided you "do not disable, hide or alter the branding link" and ship the LICENSE file. What it forbids is selling the library itself or distributing it on its own. A paid seat buys the removal of the link, not the right to use it commercially.

Two mechanics differ from open-source habit. Highcharts' source is public on GitHub, but its EULA limits modification to Personal or Educational Use and forbids distributing modified code — public source is not an open-source licence. And some vendors enforce in code: SciChart uses runtime keys locked to registered domains, and AnyStock draws a watermark until a licence key is set.

What it costs

For the code, the range runs from nothing to a few thousand dollars per developer a year. The figures below are the entry point of each licence shape for a public product, taken from each card, where the full tier list is dated.

• Nothing, with a notice: Apache ECharts, Plotly.js, KLineChart, Lightweight Charts (plus the TradingView link).
• Nothing, with conditions and a contract: Advanced Charts — no fee, the eligibility rules and marketing obligations above, and 50,000 dollars of liquidated damages per proven breach.
• Nothing, with a branding link; 64 dollars a year per developer seat without it: amCharts Stock Chart, for public sites with no login. Behind a login it is 224 dollars a seat a year.
• 732 dollars a year per developer seat: Highcharts Stock for one public application — Core at 366 dollars plus the Stock add-on at 366, as the card recorded them on 13 September 2026. Stock is not sold without Core.
• 139 dollars once, or 499 dollars a year: AnyStock's Website licence for one product on one registered domain with no login, or its SaaS licence once there is one. Each AnyChart product is licensed separately.
• About 1,350 dollars a year per developer: SciChart.js 2D, domain-locked, up to five apps or sites and 15,000 end users.

None of these numbers grows with your audience, apart from SciChart's user ceiling. That is the sharpest difference from the other licence on the chart, where real-time display is counted per person looking at it.

No library ships the prices

Every library in this category renders what you hand it. TradingView says of its libraries that you "connect your data to them through the API"; its agreement puts the feed on you in clause 2.2 and the exchange licensing on you in clause 10. The Highcharts, amCharts, AnyStock and SciChart cards all record the same thing in their data sections: nothing in the box. The one exception on any of them proves the point — Highcharts' Morningstar connector is sold only under a separate Partner-Data License and needs your own Morningstar account. Choosing a library free of charge does nothing to the cost of what it draws.

The data licence asks different questions from the code licence, and the answer to one tells you nothing about the other:

• Display or not. Exchanges price by use. Nasdaq's data policies define Display Usage as accessing its data by "display of such data on a screen or other mechanism designed for access or use by a natural person". A chart on a public page is exactly that, and each viewer of real-time data is a subscriber someone reports and pays for. What real-time market data costs walks the fee stack.
• Your own eyes or other people's. Showing prices to anyone outside your organisation is redistribution, licensed separately and priced per venue before the first viewer exists. A free or developer-tier API key usually excludes it.
• Real-time or delayed. Delayed data is licensed as a separate and far cheaper product, which is why most free financial sites show it, and exchanges require the display to say that it is delayed.
• The raw number or something computed. An indicator line calculated from licensed prices can still be licensed data. Derived data covers where the line falls.

The two licences meet awkwardly in one place. Advanced Charts' clause 2.4 requires a free, public service, and a public page is exactly where real-time exchange data is redistributed to people you do not know and cannot count in advance. Unless you already hold a data licence that covers those viewers, the free chart sits on a data bill that is not free, and the chart licence has no bearing on how large it is.

What you can do about it

Answer the four questions before you pick a library. Is it commercial, is it behind a login, is it internal, and do you ship it inside someone else's software. Those answers eliminate more of this category than any feature table. A subscription product behind a login rules out Advanced Charts under the free agreement, AnyStock's Website licence and the cheapest amCharts seat before you have looked at a single chart type.

If you need indicators and drawing tools and cannot sign the TradingView agreement, that is the real decision in this category. Lightweight Charts has neither; KLineChart is the permissive library in this catalogue that ships both; Highcharts Stock sells 48 indicators per seat; SciChart.js, for all its price, ships no indicator library. Price the seat against the weeks of writing indicators yourself.

Put the notices in the build, once. For Apache-2.0 and MIT libraries, a licences page or a bundled third-party notices file covers every library at once. For Lightweight Charts leave attributionLogo on or put a tradingview.com link on a page users can reach. For amCharts' free build the branding link stays on the chart, and the LICENSE file ships with it.

Read the contract, not the FAQ, for anything free-but-gated. The Advanced Charts FAQ tells you who may apply. The agreement tells you about the announcement you must publish, the ban on benchmarking, the sixty-day exit and the 50,000-dollar damages clause. Only the second is binding.

Price the data licence before the chart licence. The chart is the smaller number in almost every case this page describes. Work out who will see the prices, whether they are real-time, and whether they are inside your organisation — the redistribution entry and the fee guide give the questions and the exchange figures. If the answer is a public page with real-time US equities, check whether delayed or end-of-day data would do the job; the chart library will draw either.

Ask your data vendor, not your chart vendor, what you may display. No library in this category can grant display rights over prices it did not supply, and TradingView's agreement says outright that the responsibility is yours.