Summary

This URL to audio converter page pairs a client-side MP3 estimator, duration and file size from a word count and narration speed, with a direct path to heartheweb's real converter. heartheweb turns any article URL into an MP3 or a private podcast feed using forty-two AI voices across six languages. The math: about 155 words per minute for natural narration and roughly 1MB per minute at 128kbps. Estimate first, then paste the real URL on heartheweb to get the finished audio.

URL TO AUDIO CONVERTER

URL to Audio Converter: Preview Your Article's MP3

Estimate how long the MP3 runs and how large the file gets before you convert a real article on heartheweb. Adjust word count and narration speed, the numbers update live.

Run the estimator See how conversion works

Estimate your MP3 before you convert

Pick an article length, or enter your own word count, and a narration speed. Duration and file size update as you type. This mirrors how heartheweb renders the real MP3.

> STANDBY
Duration --:--
File size -- MB

Enter a word count to estimate the MP3.

HOW THE NUMBERS WORK

What the estimator assumes

155 words per minute

Natural narration reads at roughly 155 words per minute, the typical pace for calm, audiobook-style voices. Faster presets sound rushed, heartheweb's narrator-calm voice sits right around this line.

128kbps MP3 export

Every heartheweb MP3 exports at 128kbps, the standard bitrate for spoken-word audio. That works out to roughly 1MB per minute of narration, clean enough for headphones or a car speaker. Music streaming apps push higher bitrates for a reason, but a narrated voice does not need them.

Speed changes pace, not pitch

The speed selector multiplies playback rate the same way heartheweb's in-app speed control does. 1.5x and 2x shorten the runtime without the chipmunk effect on the voice, since the pitch stays fixed while only the pace changes.

THE REAL CONVERSION

What happens when you paste the real URL

The estimator above runs on a word count you type in. The actual converter on heartheweb runs on the real page: paste any article URL, pick one of forty-two AI voices across six languages, and heartheweb reads the page aloud, strips the navigation and ads, and keeps headings and pull quotes in the narration. You get an MP3 to download or a private podcast feed you can subscribe to in any client. Most conversions finish in under a minute, well before the estimate above even matters.

  • Works on most news sites, blogs, and newsletters rendered as normal HTML
  • Soft paywalls with preview text usually convert; hard paywalls that block the body do not
  • Private RSS feed means new conversions show up in your podcast app automatically
A commuter holding a phone showing a green audio waveform on a train

Common questions

Is this estimator free?
Yes. It runs entirely in your browser, no account or URL submission needed. Converting an actual article into an MP3 happens on heartheweb, where the first few conversions are free too.
Where does the 155 words-per-minute number come from?
It is the typical pace for calm, audiobook-style narration, the same range broadcast narrators and most natural-sounding TTS presets target. Faster presets like 1.5x or 2x multiply from that baseline.
Does file size really scale that simply?
For an MP3 at a fixed bitrate, yes: file size is duration multiplied by bitrate. A 128kbps MP3 runs about 1MB per minute, so a 7-minute article lands around 7MB.
Will my actual MP3 match this estimate exactly?
Close, not exact. Real articles have images, captions, and pull quotes that get skipped or paraphrased, so heartheweb's true output can run a little shorter or longer than a plain word count suggests. Treat the estimate as a planning number, not a promise, before your commute.
Can I paste the URL itself into this tool?
Not here. This estimator only takes a word count, everything runs client-side with no server calls. Paste the actual URL on heartheweb to get the real MP3 or private podcast feed.
What happens with paywalled articles?
heartheweb can only read what loads on the page. Hard paywalls that block the article body before rendering will not convert cleanly. Soft paywalls, preview text plus a login wall, usually work. If a conversion comes back short, the paywall is the first thing to check.
Do you store the articles I convert?
heartheweb keeps the generated MP3 and a private RSS feed entry so you can re-listen. It does not republish the article text anywhere public, and the feed URL is unlisted, not indexed by search engines or podcast directories.
Why does the estimator round the seconds?
Rounding keeps the number readable, terminal-style. The real MP3 duration is exact down to the frame, this estimator is a planning tool, not the final render.

Ready to hear your first article?

heartheweb converts any URL into an MP3 or a private podcast feed, forty-two voices, six languages. Try it before your next commute.

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