CodeCogs fxEditor

Licence Agreement

CodeCogs fxEditor Licence Agreement (version 4, November 2026)

This licence is dated 14 Nov 2026.

Parties

(1) ZYBA LIMITED, trading as CodeCogs, a company incorporated and registered in England and Wales with company number 5190331, whose registered office is at Broadwood, Holford, Bridgwater, Somerset ("CodeCogs", "we", "us").

(2) The organisation buying a licence, as named on its order ("Customer", "you").

1. Definitions

  • Plan: the Essential or Professional plan the Customer has bought, as described on fxeditor.codecogs.com/purchase at the time of the order or of the latest renewal.
  • fxEditor: the CodeCogs equation editor, its toolbars, plugins and JavaScript API, whether loaded from CodeCogs' servers or included in the Customer's own pages or application.
  • fxTeX Server: CodeCogs' online service that converts LaTeX into images, MathML and other formats.
  • fxTeX Pro: the CodeCogs LaTeX conversion engine compiled and built for, and locked to, the Customer's licence. Included in the Professional plan only.
  • Products: fxEditor, fxTeX Server and (where the Plan includes it) fxTeX Pro, together with their documentation, updates and any licence keys, as included in the Plan.
  • Licensed Domain: the one internet domain registered against the licence, including its subdomains.
  • Licensed Application: the one named software application (for example a mobile or desktop app) registered against the licence, in place of a Licensed Domain.
  • Licensed Property: the Licensed Domain or Licensed Application, whichever this licence is registered to.
  • Usage Allowance: the number of service loads a month included in the Plan. One service load is one occasion on which fxEditor or fxTeX Pro is started under the Customer's licence in a page or screen.
  • Rate Limit: the number of equations a second fxTeX Server will convert for the Licensed Property under the Plan.
  • Billing Period: one month or one year, as chosen at checkout.
  • Fee: the price of the Plan for each Billing Period, as shown at checkout or as later changed under clause 7.4.
  • End Users: the people who use the Licensed Property.

2. Scope

2.1 This licence covers the Essential and Professional plans, including fxTeX Pro where the Plan includes it.

2.2 The Customer confirms that it is buying for the purposes of its trade, business or profession, and not as a consumer.

3. What you may do

3.1 In return for the Fee, CodeCogs grants the Customer a non-exclusive, non-transferable licence, for as long as this licence is in force, to:

  1. embed fxEditor and use its API within the Licensed Property, so that the Customer and its End Users can write, edit and display mathematics as part of the content of the Licensed Property;
  2. use fxTeX Server, within the Rate Limit, to render mathematics for display within the Licensed Property;
  3. where the Plan includes it, load and run fxTeX Pro within the Licensed Property to render the mathematics shown there; and
  4. customise fxEditor's toolbars and appearance through the options and API documented by CodeCogs.

3.2 Mathematics that End Users create within the Licensed Property belongs to them or to the Customer, and may be stored, published and shared as part of the Licensed Property's own content.

4. One domain or one application

4.1 The licence covers one Licensed Domain (with its subdomains) or one Licensed Application. Each further domain or application needs its own licence.

4.2 The Customer may ask CodeCogs to change the Licensed Property. CodeCogs may refuse a change to a domain or application that is already licensed to someone else. Because fxTeX Pro builds are compiled for the Licensed Property, its registration cannot change within 30 days of a fxTeX Pro build being made for it.

4.3 The Customer must not use the Products, or allow them to be used, on any domain or in any application other than the Licensed Property. It must not share its licence key with anyone, or use it, outside the Licensed Property.

5. What you may not do

5.1 No standalone equation tools. The Products are licensed to enrich the Licensed Property's own content. The Customer must not use the Products, in whole or in part, to build, offer or distribute any product or service whose main purpose is to create, convert or supply equations for use outside the Licensed Property. This includes, for example:

  1. an equation editor, or equation editor app, whose output is copied, exported or inserted into other documents, websites or software;
  2. an add-in, extension or plugin for a word processor, presentation tool, spreadsheet, email client, web browser, note-taking app or other third-party software (for example Microsoft Word, Google Docs or Google Chrome);
  3. an online service or API that renders or converts mathematics for other websites, applications or users; and
  4. any other product that competes with the Products or with the services CodeCogs provides.

5.2 Clause 5.1 does not stop the Customer offering features within the Licensed Property that let End Users export or download content they created there, such as a document, worksheet or course page, where the mathematics forms part of that content.

5.3 No reverse engineering. The Customer must not, and must not allow anyone else to:

  1. reverse engineer, decompile, disassemble, decrypt or otherwise try to obtain the source code, algorithms, data structures or internal workings of the Products. This applies in particular to fxTeX Pro, including its WebAssembly and any part of it built for the Customer;
  2. copy, modify, translate or create derivative works of the Products, other than through the configuration and API documented by CodeCogs;
  3. remove, bypass or interfere with any licence key, domain lock, expiry date, usage count or other technical protection in the Products; or
  4. sell, sublicense, rent, lend, host for others or otherwise make the Products available to any third party.

Clause 5.3 does not restrict anything the law expressly allows despite such a restriction.

5.4 Branding. Where the Products display CodeCogs' name, logo, copyright notice, attribution, or links to CodeCogs (including fxEditor, and the help pages, calculator and other interfaces provided with fxTeX Pro), the Customer must not remove, hide, alter or obscure them.

6. Usage

6.1 Usage Allowance. The Products count each service load so that usage can be measured against the Usage Allowance. The allowance is not enforced by throttling: fxEditor keeps working when the allowance is exceeded. If the Licensed Property regularly exceeds its Usage Allowance, CodeCogs may ask the Customer to move to a Plan that covers its usage. If it does not do so within 30 days, CodeCogs may move it to that Plan from its next renewal, or restrict or suspend the Products.

6.2 Rate Limit. fxTeX Server applies the Rate Limit automatically. Requests above it may be delayed or refused.

6.3 No liability for usage limits. CodeCogs is not responsible for any loss of revenue, profit, business, End Users or goodwill, or for any other loss, arising from the Customer's usage exceeding the Usage Allowance or Rate Limit, from requests being delayed or refused under the Rate Limit, or from any restriction or suspension under clause 6.1. The Customer is responsible for choosing a Plan that suits its expected usage.

6.4 Usage data (counts of service loads and rendering requests for the Licensed Property) is collected only to operate, measure and bill the Products. It does not include the content of the mathematics End Users write.

7. Subscription, payment and renewal

7.1 The licence starts when the first Fee is paid. It runs for one Billing Period and renews automatically for further Billing Periods, with the Fee taken from the Customer's card at the start of each, until it is cancelled.

7.2 The Customer may cancel at any time from its licence manager. The licence then continues until the end of the Billing Period already paid for and does not renew. Fees already paid are not refundable for part of a Billing Period, except where clause 9.1(c) applies.

7.3 If a renewal payment fails, CodeCogs will retry it and tell the Customer. The licence continues for 7 days after the end of the last paid Billing Period. If the Fee is still unpaid after that, the licence ends.

7.4 CodeCogs may change the Fee for future Billing Periods by giving at least 30 days' notice before the renewal at which the change takes effect. The Customer may cancel before then.

7.5 Fees exclude VAT and other applicable taxes, which are added at checkout and shown on each invoice.

8. Ownership

8.1 The Products, and all intellectual property rights in them, belong to CodeCogs or its licensors. This licence gives the Customer only the rights set out in it.

8.2 If the Customer suggests improvements to the Products, CodeCogs may use them freely.

9. Warranties and liability

9.1 CodeCogs warrants that the Products will work materially as described in their documentation. If the Customer reports a material defect that CodeCogs can reproduce, CodeCogs will at its option:

  1. correct it;
  2. provide a workaround; or
  3. end the licence and refund the Fee paid for the unused part of the current Billing Period.

9.2 CodeCogs does not warrant that the Products will be uninterrupted or error-free, or that they will render every LaTeX input. The Customer is responsible for checking that the Products suit its purpose.

9.3 Apart from clause 9.1, all warranties, conditions and terms implied by statute, common law or otherwise are excluded to the fullest extent permitted by law.

9.4 CodeCogs is not liable, whether in contract, tort (including negligence) or otherwise, for any:

  1. loss of profits, revenue, business, contracts or anticipated savings;
  2. loss or corruption of data;
  3. loss of goodwill; or
  4. indirect or consequential loss.

9.5 CodeCogs' total liability under or in connection with this licence is limited to the Fees the Customer paid in the 12 months before the event giving rise to the claim.

9.6 Nothing in this licence limits or excludes liability for death or personal injury caused by negligence, for fraud or fraudulent misrepresentation, or for anything else that cannot be limited or excluded by law.

10. Suspension and termination

10.1 CodeCogs may suspend the Products, or end this licence by notice, if the Customer breaches clause 4 or clause 5. It may also do so if the Customer commits any other material breach and does not remedy it within 14 days of being asked to.

10.2 When this licence ends for any reason:

  1. all rights granted under it stop;
  2. CodeCogs will stop serving the Products to the Licensed Property;
  3. the Customer's licence key and any fxTeX Pro build made for it will stop working; and
  4. the Customer must remove the Products, including any copies of fxTeX Pro, from the Licensed Property and its systems.

10.3 Clauses 5, 6.3, 8, 9 and 11 survive the end of this licence.

11. General

11.1 Confidentiality. Each party will keep confidential any non-public information it receives from the other about the other's business. For the Customer, this includes its licence key, private key and fxTeX Pro builds.

11.2 Changes to this licence. CodeCogs may update this licence for future Billing Periods by giving at least 30 days' notice before the renewal at which the update takes effect. The Customer may cancel before then.

11.3 Assignment. The Customer may not assign or transfer this licence without CodeCogs' written consent. CodeCogs may transfer it to any successor to its business.

11.4 Notices. Notices may be sent by email: to the Customer, at the email address of its account; to CodeCogs, at support@codecogs.com.

11.5 Waiver and severability. A delay in enforcing any right is not a waiver of it. If any provision is found unenforceable, the rest of this licence continues in effect.

11.6 Third parties. No one other than the parties has any right to enforce this licence.

11.7 Entire agreement. This licence, together with the Plan, is the whole agreement between the parties about its subject matter, and replaces any earlier agreement about it.

11.8 Law and jurisdiction. This licence, and any dispute arising from it, is governed by the law of England and Wales, and the courts of England and Wales have exclusive jurisdiction.

11.9 Customer identification. Unless otherwise agreed, CodeCogs may identify the Customer by name and logo on its website and in marketing materials, solely to indicate the Customer's use of CodeCogs technology. Such identification shall not imply endorsement, sponsorship or partnership. The Customer may ask for its name or logo to be removed at any time.

12. Acceptance

This licence is accepted electronically by the Customer ticking the acceptance box at checkout. The email address of the person accepting it, and the date and time of acceptance, are recorded, and a dated copy is sent by email once the order is complete.

Signed by Dr W.J.D. Bateman, for and on behalf of ZYBA LIMITED