🎬 Guide hub · 23 tools · 46 guides · Updated October 7, 2026

Video and audio guides: trim, compress, convert and transcribe

These guides cover the editing jobs that come up again and again: cutting a clip to length, shrinking it for email or chat, reframing it for vertical video, adding subtitles, recording your screen or voice, converting audio formats and turning speech into text.

The tools work on files you already have or record yourself, and they run in your browser without uploading your media. GrabCast does not download videos from YouTube, TikTok, Instagram or other sites; to get a copy of a video, use the platform's own options, as explained in the guide to saving videos legally.

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Trim Video Without Losing Quality: Fast vs Precise Cuts

Trim video without losing quality: a stream-copy cut keeps every original frame, while a precise re-encode lands on the…

Add Subtitles to Video Free, No Watermark or Sign-Up

Add subtitles to a video free with no watermark: generate an SRT with AI, fix the timing, then burn it in, embed a…

No-Watermark Screen Recording for Narrated Tutorials

Record your screen free with no watermark and a clear voice track. Settings for narrated tutorials: 1080p presets, mic…

Transcribe Audio Privately: On-Device Whisper Guide

Transcribe sensitive recordings with no third-party server: run Whisper in your browser, pick a model by size, verify…

How to Convert Video to MP3 (Free Audio Extractor)

Convert a video to MP3 free in your browser: pick a bitrate, trim, normalise loudness and download. Your file is never…

How to Save Videos Legally (YouTube, TikTok, Instagram)

The official ways to save videos for offline viewing: YouTube Premium, YouTube Studio, Google Takeout, Facebook and…

Which tool do I need?

If you want to…	Use
Cut a clip to length	Video Trimmer & Subtitles
Shrink a video for email, Discord or WhatsApp	Video Compressor
Reframe to 9:16 for Reels, TikTok or Shorts	Crop & Resize Video
Turn a long video into a captioned vertical short	Shorts Maker
Turn a recording into text or subtitles	AI Voice-to-Text Studio
Summarize a video or podcast with chapters	Video & Audio Summarizer
Cut a video by editing its transcript, remove um and uh	Text-Based Video Editor
Translate subtitles into many languages at once	Multilingual Subtitle Pack
Add an English AI voice-over (dub) track	AI Video Dubbing
Extract the audio as MP3	Audio Converter
Record a tutorial with your webcam	Screen Recorder
Make a quiet recording louder	Volume Booster
Change MOV or MKV to MP4	Video Converter

Free tools in this hub

Video Trimmer & Subtitles

Trim a video and add subtitles automatically from the speech — edit, download .srt, or embed. In your browser, no watermark, no upload…

Video Compressor

Shrink a video for email, chat or the web while keeping it sharp — quality presets, resolution options and a clear size saving. 100% in…

Video Converter

Convert MOV, MKV, AVI, WebM, WMV and more to MP4, WebM, MOV, GIF or MP3 — instant stream copy when possible, quality presets, batch + ZIP.…

Crop & Resize Video

Crop or resize a video to 9:16 for TikTok, Reels and Shorts, 1:1, 4:5 or 16:9 — drag the frame or fit with a blurred background, rotate…

Shorts Maker

Turn a long horizontal video into a vertical short for TikTok, Reels and YouTube Shorts — pick the clip, reframe to 9:16, auto captions…

Merge Videos

Join video clips into one MP4 — drag to reorder, trim each clip, pick 9:16, 1:1, 4:5 or 16:9, add crossfades. Lossless fast join when clips…

Change Video Speed

Speed up or slow down a video from 0.25× to 4×, or make an 8×/16× timelapse — keeps the voice pitch natural, previews live, exports MP4.…

Video to GIF

Convert a video clip into a crisp, optimized GIF with a smart color palette — choose FPS, width and length. 100% in your browser, private…

Screen Recorder

Record your screen with system audio, mic and a webcam bubble — pause/resume, countdown, 1080p/60fps, save as MP4. Free, no watermark, no…

Voice Recorder

Record your voice online with a live level meter, pause/resume and noise reduction — trim, normalize and save as MP3 or WAV. Free, private…

Audio Converter

Convert audio or extract it from video — MP3, M4A, OGG, WAV, FLAC at 64–320 kbps or VBR, mono/stereo, sample rate, podcast loudness (−16…

Audio Cutter & Ringtone Maker

Cut MP3 and other audio on a waveform — drag start/end, fade in/out, remove a part, save as MP3, WAV, M4A or an iPhone M4R ringtone. Free…

Audio Joiner

Merge MP3, M4A, WAV and other audio files into one — drag to reorder, crossfade or gaps, per-track volume, even out loudness. Free…

Volume Booster

Make quiet audio or video louder by up to 20 dB with a limiter that prevents clipping, or auto-normalize loudness — video picture stays…

Audio to Waveform Video

Turn a podcast or song into an MP4 waveform video (audiogram) for TikTok, Reels, Shorts and YouTube — cover art, title, 4 styles, in your…

AI Voice-to-Text Studio

Transcribe audio & video to text with AI — 100% in your browser, private, free, no upload.

Video & Audio Summarizer

Summarize a video or audio file: TL;DR, key points, YouTube chapters with timestamps and a clickable transcript — Whisper transcribes on…

Text-Based Video Editor

Edit a talking-head video by editing its transcript: delete words to cut them, remove um/uh, retakes and long pauses in one click, add…

Multilingual Subtitle Pack

Turn one video or SRT file into subtitles in up to 20 languages at once — timing kept, reading-speed checks, side-by-side editing, ZIP of…

AI Video Dubbing

Add an English AI voice-over track to your video from its subtitles: translated line by line, voiced on your device with stock AI voices…

AI Clip Finder for Shorts

Find the most viral 20–45s moments in a transcript/SRT to cut into TikToks, Reels and Shorts, with hook captions.

YouTube Thumbnail Checker

Preview your own thumbnail in YouTube home, search, mobile and dark mode at real sizes — safe zones, small-size legibility, 1280×720 / 2 MB…

Template Studio

Free Canva-style templates for Reels, TikTok, Shorts, posts, carousels and YouTube thumbnails: edit text, colours, photos and music, export…

Text to Speech

Turn text into natural AI voices and download MP3 — 16 US/UK voices, runs in your browser, free, no sign-up.

Guides by tool

Frequently asked questions

Are my videos uploaded when I trim or compress them?

No. Trimming, compressing, converting, cropping and merging run in your browser using your device's processor. Large or long videos simply take longer on slower devices.

Can GrabCast download a video from YouTube or TikTok?

No. The link-based downloader was retired. Use the platform's own features, such as YouTube Premium offline viewing, YouTube Studio for your own uploads, or a data export, and then edit files you have the right to use.

Is transcription private?

Yes for the Voice-to-Text Studio: the Whisper speech model downloads once and transcribes on your device. AI Clip Finder is different, because it sends the transcript text to an AI service to pick the best moments.

Is there a watermark or length limit?

There is no watermark and no account. Practical limits come from your device's memory; very long 4K files are easier to handle if you trim first and compress second.

Which format should I export?

MP4 (H.264 with AAC audio) plays almost everywhere. For audio, MP3 is the most compatible, while WAV or FLAC keep full quality if you plan to edit again.

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