Effective and last updated: September 3, 2026.

YTMP3X is an independent Firefox extension for converting audio from a permitted public YouTube video or Short to MP3. It is not affiliated with YouTube, Google, Mozilla or Firefox. This policy covers the Firefox extension, not separate services on our website.


Opening the popup reads the selected tab's address and title to identify a supported YouTube source and display its public thumbnail. Starting a conversion requires your confirmation that you have permission to process the media and that Firefox may use your current YouTube session. You choose the bitrate. Sources are limited to 30 minutes and 100 MiB.

The extension processes the selected video's ID, title, thumbnail, duration, player status, available formats, codec, bitrate, byte length, temporary signed media address, source bytes, progress and output bytes. These are used only to retrieve, validate, label, convert and save the requested audio. It does not monitor unrelated tabs or compile browsing history.


The extension contacts www.youtube.com for the requested player's information, HTTPS googlevideo.com subdomains for media, and i.ytimg.com for the thumbnail. The selected video ID/address or media request identifies what you asked to process. Those services receive normal network information, such as IP address and browser headers, under their own privacy practices.

For this reason Firefox's installation prompt declares browsingActivity and websiteContent. These categories cover the selected source and necessary website requests, not sale of browsing history or behavioral analytics. No conversion request or media is sent to a YTMP3X backend. Viewing a support or website link is a separate action and is subject to that site's practices.


Player/media requests use credentials: include. Firefox may attach cookies permitted by its normal browser rules directly to YouTube/Googlevideo requests. YTMP3X does not request the cookies API, read cookie values, collect passwords or login tokens, or extract account/profile information. It cannot promise that these requests are anonymous.

A packaged function may run in the YouTube page's MAIN world. If needed, an inactive tab for the same public video may be opened for resolution. Returned fields are limited to the requested public player/media data, not messages, subscriptions or account details. No private, members-only, age-restricted, DRM-protected or unavailable-content bypass is provided.


Packaged FFmpeg/WebAssembly converts media locally in Firefox. No source media or finished MP3 is uploaded to YTMP3X. Source/output data and progress are held in memory while the processing page needs them. Some completion/diagnostic state and output Blob references may remain until that page closes; cancellation and cleanup release resources as applicable. We do not claim immediate physical erasure of browser memory.

The extension does not store a persistent installation ID or conversion history, and does not use browser.storage, localStorage, sessionStorage or IndexedDB for user records. Firefox's own downloads/history/cache features may retain their normal records. Downloaded MP3s remain where you save them until you delete them; uninstalling the extension does not remove these files.

Local troubleshooting routines remain in the code, but their normal UI is hidden and they never upload automatically. Any deliberately exported diagnostic file is local, excludes full signed media addresses/cookies/tokens/account fields, and stays under your control. Check a report before voluntarily sending it to support.


The extension has no analytics, advertisements, fingerprinting, install tracking, automatic telemetry, payment system, subscription or licensing server. It does not extract names, emails, passwords, financial/health information, contacts, communications, precise location, keystrokes or unrelated page content. Necessary third-party network traffic described above is not a claim that no data leaves the browser.


We do not sell conversion information or use it for advertising, lending or unrelated purposes. Google/YouTube receive the direct requests needed for your conversion. There is no developer-operated conversion database.

If you contact support, we receive what you voluntarily send, such as your email, message and any attached report. Do not send cookies, tokens, passwords or signed media URLs. Support information is used to respond to your request, not for extension tracking. Contact us to request deletion of correspondence, subject to any applicable legal retention obligations.


You may decline installation consent, leave the per-job checkbox unselected, cancel a conversion, close its page, revoke site access in Firefox, disable or uninstall the add-on, and delete local files. The popup may retrieve the selected public thumbnail when opened; declining conversion prevents the conversion, not a network request that already occurred. Changing cookie/site-access settings may affect whether conversion works; do not weaken browser protections to use it.

HTTPS, validated YouTube/Googlevideo hosts, bounded messages and media sizes, sender checks and locally packaged executable code reduce risk. No remote JavaScript/WASM or eval is used. No software can guarantee absolute security.


The extension is a general-purpose utility, not directed to children. It has no accounts, social features or behavioral advertising. We will update this policy and Mozilla disclosures if practices change. A privacy notice does not grant rights to third-party content; use only media you are entitled to process.

Website: https://youtubetomp3x.com/

Support: https://youtubetomp3x.com/contact

Privacy and security contact: support@youtubetomp3x.com