OnlyMP3 Converter Review: How to Download YouTube Audio Safely?

Part 1: How OnlyMP3 Converter Works?

OnlyMP3 (onlymp3.io) is a free online YouTube video to MP3 audio converter. You can convert YouTube videos to MP3. The conversion process is entirely web-based; you don't need to create an account or download and install any programs to directly save your favorite music videos, tutorials, speeches, and interviews to Dropbox or your local device.

Support URL	Output Format	File Save Path	Output Kbps	Sign Up or Not
YouTube only	MP3 only	Dropbox or Browser	128 kbps	❌

Step 1: Open the website directly here: https://en.onlymp3.io/101/.

Step 2: Copy the video link from YouTube and paste it into OnlyMP3.

Step 3: Click "Convert" and then choose to save the video to Dropbox or download it directly to your browser.

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Part 2: Key Features of OnlyMP3 Converter

💡 Can You Use OnlyMP3 on Your Phone?

• OnlyMP3 is an online converter compatible with Chrome, Firefox, Safari, and Edge browsers. Therefore, as long as you have this type of browser installed on your phone, you can open the OnlyMP3 converter in the browser and convert YouTube videos to MP3.

💡 Which URLs does OnlyMP3 Support for Online Conversion?

• The OnlyMP3 website explicitly states that it is a YouTube to MP3 converter; therefore, it can only analyze valid YouTube URLs. A valid URL refers to a YouTube video that is no longer than 6 hours.

💡 Does OnlyMP3 Support Formats Other than MP3?

• As the name suggests, OnlyMP3 can only convert to MP3 format and does not support AAC and FLAC formats. The MP3 format is compatible with almost all systems, hardware devices (mobile phones, media players, car stereos), software players, and streaming media platforms.

💡 Can You Customize the Bitrate or Audio Quality?

• OnlyMP3 downloads videos to 128 kbps MP3 format by default. It does not offer options for custom bitrate and audio quality.

💡 Are There any File Size or Conversion Time Limits?

• OnlyMP3 YouTube to MP3 converter offers unlimited conversions of YouTube videos under 6 hours. Although it limits YouTube videos to no more than 6 hours, very few YouTube music videos, interview videos, or podcasts exceed 6 hours. So there's no need to worry about this.

💡 Can DRM-Protected Content be Converted?

• OnlyMP3 cannot convert or download DRM-protected, age-restricted, or country-blocked YouTube videos. Downloading DRM-protected content is illegal, and very few online converters can actually do it.

💡 Is There Customer Support If You Encounter Conversion Problems?

• OnlyMP3 converter's website provides an official contact email address ([email protected]). You can try contacting them using this email address, but it's unclear how quickly they process emails.

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Part 3: Do You Know the OnlyMP3 Extension?

There is an even faster way to convert YouTube to MP3 than using the online OnlyMP3 converter: using an OnlyMP3 extension. Although OnlyMP3 officially states that it provides extensions for Firefox and Opera, in testing, only the Firefox extension is available.

• Firefox Extension: https://addons.mozilla.org/en-GB/firefox/addon/onlymp3/

Install the OnlyMP3 extension in your Firefox browser, and you can start downloading YouTube to MP3 simply by opening the YouTube webpage and clicking the extension icon - no need to copy URLs to third-party websites. The process is faster than the OnlyMP3 online converter.

Step 1: Open the OnlyMP3 extension installation link in the Firefox browser.

Step 2: Click "Add to Firefox" and confirm to install in the browser. If any privacy requests appear, please do not select them to avoid privacy leaks.

Step 3: Open the YouTube webpage in your Firefox browser and locate the video you want to download.

Step 4: You do not need to log in to your YouTube account. Just open the extension in the upper right corner and click "Convert to MP3" to start the YouTube to MP3 conversion.

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Part 4: More Popular OnlyMP3 Converter Alternatives

While OnlyMP3 Converter stands out among many online YouTube to MP3 converters, it inevitably has the following limitations:

So, are there more perfect MP3 converters?

Any Video Converter - Safer OnlyMP3 Alternative

Support URL	Output Format	Output Kbps	Free or Not	Bulk Files
1000+ websites	MP3, M4A, FLAC, WAV, and more	The highest bitrate of the source video	Free convert	✅

Any Video Converter is not just a free YouTube to MP3 converter but also a multi-website downloader, media file editor, and intelligent AI generator.

Not limited to YouTube alone, it also supports downloading and converting 1000+ mainstream media platforms. Its built-in browser significantly improves download and conversion success rates to 99%. You can directly download videos as MP3 or easily switch downloaded content to other video/audio formats. Whether saving online course audio, creating podcast material, or making a personal music library, Any Video Converter provides a stable and efficient solution.

How to Convert Videos to MP3 with Any Video Converter

For local videos, you can use the "Format Convert" tool to convert them to MP3 format. For online videos like those on YouTube, you can use the "Video Download". Here, we take converting online videos as an example.

Step 1: Launch Any Video Converter and click to enter "Video Download".

Step 2: Click the to unlock the built-in YouTube browser (which can effectively improve the download success rate).

Step 3: Play the videos, playlists, and music you want to download to MP3. Then click "Parse Now". In the settings on the right, don't forget to enable the "Download as MP3" option.

Step 4: Click "Download Now" to download videos as MP3.

YouTube Multi Downloader - Online OnlyMP3 Alternative

Website	Support URL	Output Format	Output Kbps	Sign Up or Not	Bulk Files
https://ytmultidownloader.com/	YouTube only	MP3, WEBM	128kbps	❌	✅

YouTube Multi Downloader, just like it said, can save YouTube videos to your computer or mobile phone in MP4, MP3, and WEBM. Most importantly, it can download YouTube playlists to MP3. Although YouTube Multi Downloader can batch download videos as MP3, it processes them sequentially during actual conversion. This means that it can receive your playlist links all at once, but the MP3 files are downloaded one by one, and the download will be interrupted if you close the webpage. Therefore, you must not close the website and must ensure a stable internet connection during the conversion process.

How to Convert YouTube Videos to MP3 with YouTube Multi Downloader

Step 1: Open the YouTube Multi Downloader website and the YouTube website.

Step 2: Copy the YouTube video link, then switch back to the YouTube Multi Downloader website and paste it in.

Step 3: Start fetching video details, then click "Load Options". Select MP3 format from the displayed options to download.

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Part 5: FAQs about OnlyMP3

Q1: How can I convert YouTube videos to MP3 on a Mac?

OnlyMP3, Any Video Converter, and YouTube Multi Downloader can all convert YouTube videos to MP3 on a Mac. For online websites like OnlyMP3 and YouTube Multi Downloader, you can simply open their websites in a browser on your Mac to start the conversion. While Any Video Converter has a Mac version, you can install it on your Mac first, then go to "Video Download" and use the built-in YouTube browser to download as MP3.

Q2: What is the best free MP3 converter?

From the perspective of safety and reliability, software (Any Video Converter) is definitely better than free online MP3 converters. Unlike online YouTube to MP3 converters like OnlyMP3, Any Video Converter completes the conversion process entirely on your local computer, eliminating the risk of privacy leaks. After installation, the program can convert video formats without an internet connection (except for downloading YouTube videos as MP3), unaffected by network fluctuations.

Most free online converters have strict limits on file size and number of conversions, while Any Video Converter is completely free and has no file size limits, making it far superior to those online converters.

Q3: How to avoid viruses from OnlyMP3 converter?

First, when using a website, check if it has proper registration, a copyright statement, and developer information to avoid visiting fake websites with numerous pop-up ads. Second, when installing OnlyMP3 extension, be sure to disable privacy requests. You can also install browser ad-blocking plugins to block malicious ads and redirect links.

If you are very concerned about the source of OnlyMP3, you can directly choose a reputable and legitimate software: Any Video Converter.

Q4: Can I download a YouTube playlist to MP3?

OnlyMP3 cannot download YouTube playlists as MP3. The article mentions YouTube Multi Downloader and Any Video Converter, which can download YouTube playlists as MP3.

How to Download a YouTube Playlist to MP3 >>

Q5: What are the reviews of OnlyMP3?

Trustpilot shows OnlyMP3 with a rating of 4.7 based on 68 reviews. The latest positive review was on December 22, 2025.

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Final Thoughts

In conclusion, OnlyMP3, as a free online YouTube to MP3 converter, can indeed meet basic audio extraction needs. It requires no registration and supports direct saving to Dropbox, making it a lightweight MP3 converter. However, we must also be aware of its limitations: redirecting pages, no batch download, and no customization options can all negatively impact your conversion experience.

In comparison, Any Video Converter offers a more stable, efficient, and secure MP3 conversion solution. Whether for learning, creative work, or personal entertainment, it provides long-lasting and high-quality service support. Of course, the final choice depends on your specific needs and requirements for security and functionality.