GrowMyTube
📈 Free toolkit for YouTube creators

Grow your YouTube channel with free creator tools

Captions, Shorts, thumbnails, channel art, video converting and compressing, and topic ideas: the tools a growing channel needs. Everything runs in your browser. No sign-up, no watermark.

Choose a toolTry auto captions
  • 🎁 100% free
  • 🚫 No sign-up
  • 🔒 Stays on your device
  • ✨ No watermark

All tools

Everything you can do on GrowMyTube

GrowMyTube is a set of free tools for people who make YouTube videos: caption a video, turn a horizontal clip into a Short, size a thumbnail or channel banner correctly, convert and compress files, and find topic ideas. Each tool has its own page with a guide, limits and answers to common questions. Here is what every tool does.

Video tools

Auto Captions

Add a video or audio file and get timed captions in minutes. The Whisper speech model runs on your own device, so nothing is uploaded. Download an SRT or VTT to upload in YouTube Studio, or burn one of 24 animated styles, including one or two words at a time in the centre, into the video itself.

  • Nothing is uploaded. The speech model runs on your device. Your video, which may be unpublished, never reaches a server.
  • SRT, VTT and TXT export. Upload the SRT or VTT in YouTube Studio as a subtitle track, or keep the plain text as a transcript.
  • 24 animated caption styles. Word-by-word captions with highlights, boxes, glow and gradients, with your own colours, fonts and animation.

Video to MP4 Converter

Convert a video file into an MP4 with H.264 and AAC. When the file is already compatible it is rewrapped in seconds without losing quality, otherwise it is re-encoded. Runs on your device.

  • Fast copy when possible. MOV and MP4 files that already contain H.264 and AAC are rewrapped without re-encoding, so there is no quality loss.
  • H.264 and AAC output. The most widely compatible combination, and the one YouTube recommends for uploads.
  • Even dimensions and fast start. Output sizes are made even and the index is moved to the front so the file plays and seeks cleanly.

Video Compressor

Choose a target size and the compressor works out the bitrate to hit it. Use it to send a draft for feedback by email or chat. For the final upload to YouTube, keep your original quality.

  • Target-size mode. Pick a size and the tool calculates the bitrate to land at or just under it, instead of guessing at quality settings.
  • Warns when quality will suffer. If the target is very small for the video length, the tool says so before you wait.
  • Standard H.264 and AAC. The output plays everywhere, including phones, browsers and chat apps.

YouTube Shorts Maker

Turn a horizontal clip into a vertical 1080 by 1920 video. Choose a blurred background or a centre crop, pick the start and length, and download an MP4 ready for YouTube Shorts. Runs in your browser.

  • Blur-fill or crop. Keep the full picture over a soft blurred copy of itself, or zoom in to fill the screen. You can move the crop left, centre or right.
  • Trim built in. Choose where to start and how long to run, and see the length compared with the 3 minute Shorts limit.
  • Two output sizes. 1080 by 1920 for the best quality or 720 by 1280 for a faster result on a phone.

MP4 to MP3

Extract the audio from a video file as an MP3. Use it to publish a podcast version of a video, share a voice recording or keep the sound of an interview. Runs on your device.

  • Fast. Only the audio is processed, so it is much quicker than converting video.
  • Choose the bitrate. From small speech files to higher quality music.
  • Works with common formats. MP4, MOV, WebM, MKV and more.

Video to GIF

Pick a few seconds of a video and turn them into a looping GIF. Useful for blog posts, chat reactions and previews of a longer video. Runs on your device.

  • Control the length. Choose the exact start and duration.
  • Size and frame rate. Balance sharpness against file size.
  • Good colour palette. A per-clip palette gives better colours than a generic one.

Screen Recorder

Record a tutorial, a bug report or a walkthrough straight from your browser. Choose the whole screen, a window or a tab, add your microphone, and download the recording when you stop.

  • Screen, window or tab. Record exactly what you need to show.
  • Microphone option. Narrate as you go.
  • Nothing is uploaded. The recording is made and stored on your device.

Thumbnail and channel tools

YouTube Thumbnail Resizer

Drop in an image and get a 1280 by 720 thumbnail under the 2 MB limit. Choose crop to fill or fit with a blurred background, move the crop, and download a JPG or PNG. Runs in your browser.

  • Exact YouTube size. 1280 by 720 pixels, a 16:9 ratio, as YouTube recommends.
  • Stays under 2 MB. The tool tunes JPG quality to land under the limit and tells you the final size.
  • Crop or fit. Fill the frame, or keep the whole picture over a soft blurred background.

YouTube Banner Resizer

Resize any image into YouTube channel art. A guide shows the centre safe area that appears on every device, so your name and logo are never cropped. Runs in your browser.

  • 2560 by 1440 output. The size YouTube recommends for channel art.
  • Safe-area guide. The centre 1546 by 423 pixels that show on every device is outlined on the preview.
  • Under 6 MB. JPG quality is tuned to fit the limit.

Channel Profile Picture Maker

Drag your photo inside a circle preview, zoom, add a coloured ring and a background, and export a square picture for your YouTube channel icon.

  • Live circle preview. See exactly what viewers will see, since YouTube shows channel icons as circles.
  • Ring and background options. Solid or gradient rings, including a YouTube red, and a background colour.
  • Square export. Upload the square version and let YouTube round it, or export a circle with transparent corners.

Background Remover

Remove the background from a portrait photo and download a transparent PNG. Use it to place yourself on a bold thumbnail background. A small open model downloads once and runs on your device.

  • Runs on your device. The model runs in your browser, so your photo is not uploaded.
  • Made for portraits. Good at people, including hair and shoulders.
  • Transparent PNG. Drop it onto any colour or image.

Creator tools

Video and Shorts Checker

Read a video file on your device and get a plain verdict: Short or standard video, the recommended settings, and anything worth fixing before you upload.

  • Short or not. A Short must be vertical or square and no longer than 3 minutes. The checker tests both.
  • Resolution and ratio. Shows the pixel size and the nearest common ratio, such as 16:9 or 9:16.
  • Plain next steps. Each warning links to the tool that fixes it.

Subtitle Converter

Convert subtitles between SRT, VTT and TXT, move every timestamp earlier or later by a number of seconds, and remove sound descriptions like [Music]. Runs in your browser.

  • SRT, VTT and TXT. Convert in any direction between the three common formats.
  • Shift timing. Fix a file that is a constant amount early or late by moving every timestamp.
  • Remove sound descriptions. Strip [Music], (laughs) and *cough* style lines that speech models invent.

Tags and Hashtags Generator

Type your topic and pick a type of video. Get a tidy list of tags and a short list of hashtags, with a counter for the 500 character tag limit and a one-click copy.

  • Live character count. YouTube allows about 500 characters of tags in total. The counter tells you when you are close.
  • Phrases from your topic. Common ways people search for a topic, such as how to, for beginners, tips and explained.
  • Hashtags too. A short list of hashtags, with a reminder to keep them few.

Why everything runs on your device

Most online converters upload your file to a server, process it, and send it back. That means waiting for an upload, trusting a stranger with a video you may not have published yet, and often a watermark or a paywall at the end. GrowMyTube works differently: the processing code is downloaded to your browser and runs on your own phone or computer, so your files never leave it.

It also keeps the service free to run. There is no video processing bill when your own device does the work, which is why there are no daily limits and no accounts.

Frequently asked questions

Is GrowMyTube free?

Yes. Every tool is free, with no sign-up and no watermark. The site may show ads to cover its costs.

Will these tools grow my channel?

They help you publish better: captions, correctly sized Shorts and thumbnails, and clean subtitle files. Growth still comes from the videos you make, and nothing here guarantees views or subscribers.

Are my files uploaded to a server?

No. The tools run in your browser, so your videos and images are processed on your own device and are not uploaded.

How can it work without a server?

Modern browsers can run powerful code locally. We use FFmpeg compiled to WebAssembly for video, the open Whisper model for captions, and the canvas for image tools.

Why are some tools slow on my phone?

Because your device does the work. Shorter files and lower resolutions help, and desktop browsers are usually faster.

Which browsers are supported?

Recent versions of Chrome, Edge, Safari and Firefox. WebGPU speeds up captions and background removal in browsers that support it. Screen recording needs a desktop browser.

Is GrowMyTube affiliated with YouTube?

No. It is an independent project and is not affiliated with, endorsed by, or sponsored by YouTube or Google.