Convert 200+ format pairs. Compress video. All on your PC.
Shrynk is the Windows app that absorbed ConvertET: data, images, Markdown, audio, video, and ebooks in one registry — plus the local video compressor. Files stay on disk. The box below converts one still image or compresses one clip — in this tab, nothing uploaded.
What the desktop app actually does
Data
JSON, CSV, YAML, XML, TOML, and TXT encodings. Delimiters and GBK/UTF-8 when the pair needs them.
Images
JPEG, PNG, BMP, WebP, GIF mesh, SVG → bitmaps, rasters → ICO. No cloud resize.
Documents
Markdown → HTML (optional CSS) and Markdown → DOCX. Not PDF→Word — we do not fake that.
Audio
MP3, AAC, FLAC, OGG, OPUS, M4A, WAV, all-to-all via bundled FFmpeg.
Video convert
MP4, AVI, MKV, MOV, WebM, FLV, GIF, plus extract audio to six formats.
Ebooks
EPUB, MOBI, AZW3, TXT, RTF, FB2, PDF out. Calibre on PATH for most ebook cards.
Try one file in this tab
Convert a still image here, or compress one video under 100MB. Nothing is uploaded. Folders, audio, video convert, ebooks, ICO, and large files belong in the Windows app.
How the browser preview works
Stills use the canvas in this tab. Video uses ffmpeg.wasm only when you start a compress. For folders or other formats, install the desktop app.
Image pairs: JPEG quality default 90, optional max width, GIF first frame. Video: CRF 28/23/18 or a target size — same map as desktop compress.
No account, no watermark. Stills over 25MB, video over 100MB, ICO, audio, or a folder belong in the Windows app.
Frequently asked questions
Is this only a browser video compressor?
No. The Windows app is the product: ConvertET’s 200+ format pairs plus video compression. This page previews one still image (canvas, ≤25MB) or one video compress (≤100MB). Audio, video convert, ebooks, ICO, and folders stay in the desktop app. Read the docs.
Are my files uploaded?
No. The browser tool encodes in the tab. The desktop app reads and writes local paths. License activation is a network call; media is not. Details: Local files & privacy.
Which formats can I convert?
Six categories — data, image, document, audio, video, ebook. The live list is Supported formats. Compress mode always writes MP4 (H.264 + AAC). We do not convert PDF to Word.
What's free vs $9?
Install is free. Free: one file at a time, compress ≤100MB. Pro is $9 once: unlimited compress size and batch convert/compress. Free vs Pro.
Why is the first browser compression slow?
Only the Compress tab downloads the ~30MB WebAssembly ffmpeg build (once, then cached). Convert image uses the canvas in this tab and does not load ffmpeg. Desktop uses bundled FFmpeg and skips that wait.
How-tos for specific limits and conversions. Product behavior lives in Docs. All posts →
File conversion guides
Convert MP4 to MP3
Extract the soundtrack. Bitrate 192k default. Works for MKV and MOV too.
Convert MP4 to WAV
PCM for editors. No bitrate slider. Huge files on purpose.
PNG to WEBP (read first)
This build’s WEBP encode is PNG bytes under a .webp name.
Convert WEBP to PNG
Keep transparency and sharp UI. Photos that must be JPEG have their own guide.
Convert PNG to JPG
When a form forbids PNG. Quality 90. Screenshots will ring.
Convert M4A to MP3
iPhone Voice Memos and iTunes files Windows players accept.
Convert MKV to MP4
AVI and WebM use the same panel. Compress is a different button.
Convert SVG to PNG
Set the pixel width the form named. Transparent by default.
Convert WEBP to JPG
Older apps still choke on WEBP — convert photos locally without uploading them.
Convert GIF to MP4
Same clip, often 5–10× smaller, and chat apps will play it anyway.
Convert a Whole Folder at Once
One mapping per run, output next to input, convert and compress in the same Windows app.
Video compression guides
Compress a Video for WhatsApp Without Losing Quality
WhatsApp's size limits explained, plus the fastest way to shrink your clip.
How to Compress Video Without Losing Quality
The CRF setting explained in plain English, and how to pick the right number.
How to Compress a Video to Email It
Get under Gmail's and Outlook's attachment limits in under a minute.
How to Reduce MP4 File Size Without Re-Recording
Five practical ways to shrink an MP4, from quick wins to advanced settings.
Compress a Video for Discord's 10MB (or 25MB Nitro) Limit
Hit Discord's exact upload cap every time with target-size compression.
Best Video Settings for Instagram Uploads
Why Instagram re-compresses your video — and how to beat it to the punch.
How to Reduce 4K Video File Size for Sharing
4K files are huge — here's how much you can shrink them and still look sharp.
Convert and Compress MOV to MP4 (iPhone Videos)
Why iPhone .MOV files are so large, and how to shrink them for any device.
Best Video Compression Settings: A Practical Cheat Sheet
CRF, bitrate and resolution — the only three settings that actually matter.
How to Batch Compress Many Videos at Once
When you outgrow one-file-at-a-time browser tools, here's the faster path.
Compress a Video for TikTok Without Getting Rejected
Android's 72MB app limit is far tighter than the 10GB web uploader — here's how to hit it.
Compress a Video for X (Twitter)
Beat the 512MB, 140-second limit without mixing up trimming and compression.
How to Compress a Video for YouTube
No hard size cap, but a leaner file means faster uploads and processing.
MP4 vs MOV vs WEBM vs MKV
Which video format should you actually use? A plain-English comparison.
Reduce Video Size on iPhone or Android — No Computer
What the built-in phone "tricks" actually do, and what works instead.
Compress a Video for Facebook: Feed vs Stories vs Reels Limits
Facebook's video limits differ by placement — here's how to export for each one.
Compress a Video for LinkedIn Without Losing Professional Polish
5GB and 15 minutes is generous — native uploads beat pasted links for reach.
Compress a Video for Slack
1GB per file on every plan, but screen recordings and camera clips need different settings.
Compress a Zoom Recording Before Sharing It
Meeting recordings compress far more aggressively than regular video — here's why.
Compress Videos to Save Google Drive Storage Space
15GB shared storage fills fast — compress before you upload, not after.