Online teleprompter

Key takeaways

• Pace in words per minute, not a scroll speed: after one minute at 155 wpm the reading line is on word 155, whatever the text size.
• Start at 155: the median of 21 NASA videos we measured was 154 wpm, and the middle half spoke at 133 to 167.
• Record while you read: the camera preview sits behind the text and the take is saved on your device (Chromium saved an MP4 file; Firefox saved a WebM file (VP8 video, Opus sound); WebKit saved nothing: there was no camera for it in our test, so Safari is untested).
• Change the pace while reading with the arrow keys; the line stays on the same word.
• Mirror the text for a beam-splitter glass, count down three seconds, or go full screen.
• Free, no account, no app: it runs in the browser on a computer, tablet or phone.

How the scrolling works

A teleprompter that scrolls by pixels per second reads faster in a big font than in a small one, because each line holds fewer words. This one moves by words: after t seconds at a pace of P words per minute the reading line sits on word t × P ÷ 60. A bigger font or a narrower window changes how far the text moves, not how fast you have to read.

The yellow line is the reading line, at about a third of the way down so you see what is coming. Words you have passed fade. If you speed up or slow down while reading, the line stays on the word you are on and continues from there at the new pace.

Measured: how fast people actually speak

We measured pace on 21 public domain NASA videos on Wikimedia Commons that have human-written English captions: 11 short explainers, 5 interviews, 3 briefings and 2 live shows, 51,094 words in 6.1 hours. Pace is the number of caption words divided by the time from the first caption to the last, so pauses, applause and breaths count, the way they do when you read a script. 3 more videos were left out because the speech recognition found less than 30% of their caption words in the audio: they are music with text on screen, and their captions are for reading, not speech. NASA video is generally not subject to copyright in the United States, according to NASA's media guidelines. The captions, the figures and the scripts are kept with the page's evidence.

The middle half of the videos spoke at 133 to 167 words per minute, and the median was 154, so the tools start at 155. Short explainers were faster (161) and briefings slower (125), because a briefing is full of pauses and questions. Audiobook readers in LibriSpeech, another set we measured, averaged 157. When only the time someone is actually talking counts, the median rises to 168: that is how fast the words come, without the breaks.

Record yourself while you read

Press "Record with my camera" and allow the camera and microphone. The camera picture appears behind the text, mirrored like a mirror so moving feels natural; the recording itself is not mirrored. "Record a take" restarts the script, counts down and starts recording; "Stop recording" ends the take and shows it with its length and size. We tested it in three browser engines: Chromium saved an MP4 file; Firefox saved a WebM file (VP8 video, Opus sound); WebKit saved nothing: there was no camera for it in our test, so Safari is untested. If your editor does not open a WebM file, our free WebM to MP4 converter changes it in the browser.

Put the browser window as close to the camera as you can so your eyes stay near the lens. On a laptop that means a narrow window at the top of the screen.

Once you have a take, Koldflux can turn it into a week of content: it finds the strongest moments of a recording and makes Shorts with subtitles and carousels you review before export.

Free tools:Convert WebM to MP4Transcribe the takeTrim the take

How long will my script take?

At 155 words per minute a 150 word script takes about 0:58. The tool shows the length of your script as you type and the time left while you read.

Mirror mode and teleprompter glass

A hardware teleprompter puts a screen under an angled sheet of glass in front of the lens. The glass reflects the screen toward you, which flips the text left to right, so the screen has to show it mirrored for the reflection to read normally. Tick "Mirror the text" when you use a tablet or phone in such a rig. Without glass, leave it off.

Tips for reading naturally

• Write the script the way you talk: short sentences and the words you would use out loud.
• Do one read at your natural pace, then set the pace to match and record.
• Leave a blank line where you want a pause; the line keeps moving, which gives you a beat.
• Keep the window small and near the lens so your eyes do not travel.
• Record two or three takes; a later take is usually more relaxed.

How it works and why it is private

Everything runs in the page. The script is kept in your browser's own storage so it is still there when you come back; it is not sent anywhere. The teleprompter asks for the camera and microphone only when you press the record button, and the recording is made by your browser and kept on your device until you download it.

How the numbers were measured

We measured pace on 21 public domain NASA videos on Wikimedia Commons that have human-written English captions: 11 short explainers, 5 interviews, 3 briefings and 2 live shows, 51,094 words in 6.1 hours. Pace is the number of caption words divided by the time from the first caption to the last, so pauses, applause and breaths count, the way they do when you read a script. 3 more videos were left out because the speech recognition found less than 30% of their caption words in the audio: they are music with text on screen, and their captions are for reading, not speech. NASA video is generally not subject to copyright in the United States, according to NASA's media guidelines. The captions, the figures and the scripts are kept with the page's evidence. The recording formats were checked with the teleprompter itself in headless Chromium, Firefox and WebKit with a test camera: Chromium saved an MP4 file; Firefox saved a WebM file (VP8 video, Opus sound); WebKit saved nothing: there was no camera for it in our test, so Safari is untested.

Questions people ask

Related

Sources and how we checked

1. Wikimedia Commons: NASA videos with English captions (TimedText), public domain (read 2026-10-11)
2. NASA Brand Center: Images and media usage guidelines (read 2026-10-11)
3. LibriSpeech ASR corpus (OpenSLR 12), CC BY 4.0 (read 2026-10-11)
4. MDN: MediaDevices.getUserMedia() (read 2026-10-11)
5. MDN: MediaRecorder (read 2026-10-11)

Reviewed October 11, 2026. The speaking pace was measured on the human captions of 21 public domain NASA videos; the captions, figures and scripts are in data/seo/hub/evidence/2026-10-11/speech-rate.