FastestDL
Free browser-based tools for working with files — no account, no watermarks, no nonsense. Most tools run 100% in your browser, nothing uploaded to a server.
Video, Photo & Audio Compressor
Compress 4K video, MKV, MP4, MOV without losing quality. Compress JPEG, PNG, WebP photos and MP3 audio. H.264, H.265, VP9, AV1 — free, up to 2 GB, no signup.
Free online file compressor — compress video online without losing quality, reduce image size, shrink audio files. Supports MP4, MKV, WebM, JPEG, PNG, WebP, PSD, MP3, FLAC and more. Up to 2 GB, no signup, works on mobile and desktop.
Frequently Asked Questions
What video codec should I use?
H.264 is the safe default — every device and browser plays it and encoding is fast. H.265 produces files roughly 40–50% smaller at the same visual quality but takes longer to encode. VP9 is a solid open-source option for web video. AV1 gives the best compression of all four but is the slowest — worth it for archiving, not for quick exports. For detailed codec comparisons and tested CRF values, see our video compression guide.
What CRF value should I use for video?
CRF controls the trade-off between quality and file size — lower numbers mean better quality and larger files. For H.264, CRF 18–23 is visually transparent to most viewers. For H.265, CRF 24–28 gives equivalent results. The default CRF 23 (H.264) is a reliable starting point that typically reduces file size by 60–70% with no perceptible quality loss on standard content.
What's the best image format for compression?
WebP is the practical sweet spot for web images — typically 25–35% smaller than JPEG at the same quality, with full support across all modern browsers. AVIF is more efficient still (often 40–50% smaller than JPEG) but encoding is slower. JPEG remains the most universally compatible option. PNG is lossless, so it won't reduce file size for photos — use it only when you need a transparent background or pixel-perfect accuracy.
What audio bitrate should I choose?
For music, 128 kbps MP3 is acceptable for casual listening, 192 kbps is high quality, and 320 kbps is archival-grade. For voice, podcasts, or spoken content, 64–96 kbps is more than enough. Opus is the most efficient codec — 96 kbps Opus sounds noticeably better than 128 kbps MP3 and is the best choice when file size matters most.
Does compressing a file multiple times reduce quality?
Yes, for lossy formats (H.264, H.265, JPEG, MP3). Each re-encode introduces a new round of compression artifacts on top of the existing ones, and quality degrades faster than it did from the original. Always compress from the original source file when possible. Lossless formats like PNG and FLAC don't have this problem — you can re-encode them as many times as you like without any quality loss.
What file formats are supported?
Video inputs: MP4, MKV, AVI, MOV, WMV, FLV, WebM, M4V, TS, MPEG, 3GP, and more. Photo inputs: JPEG, PNG, WebP, GIF, BMP, TIFF, HEIC, AVIF, ICO, TGA, PSD, EPS, and AI files. Audio inputs: MP3, M4A, AAC, WAV, FLAC, OGG, Opus, WMA, and AIFF. If your file isn't listed, try the Converter tab — it handles a broader range of format transformations.
Format Converter & Audio Extractor
Extract audio from video (MP3, M4A, WAV), convert AVI to MP4, WMV to MP4, HEIC to JPG, WebP to JPG, AVIF to JPG, and more. Free, no watermark, no signup.
Free online format converter — convert MP4 to MP3, MKV to MP4, MOV to MP4, video to GIF, PSD to PNG, AI to JPG and more. Fast video converter online, no watermark, no signup, works on mobile and desktop.
Frequently Asked Questions
What's the difference between MP4, MKV, and MOV?
MP4 is the most widely supported container — every device, browser, and platform plays it without issue. MKV is a flexible open container that supports multiple audio tracks, subtitles, and virtually any codec, but some older devices won't play it natively. MOV is Apple's container and works seamlessly on Mac and iOS. All three can contain the same H.264 or H.265 video — the container is just the wrapper, not the quality.
Does converting a video change the quality?
It depends on whether the conversion re-encodes the video. If you're just changing the container (e.g. MKV to MP4 with the same codec inside), quality is identical. If the codec changes, there's a small quality loss from re-encoding — but at a reasonable bitrate it's rarely noticeable. Converting from a lossy format like H.264 repeatedly will degrade quality over time, so always convert from the best source you have.
How do I convert a video to a GIF?
Select your video file and choose GIF as the output format. The converter automatically scales it to 480px wide at 12 fps to keep the file size manageable — GIFs are not efficient and get very large at high resolutions or frame rates. For a short clip (under 10 seconds) GIF works fine for sharing. For anything longer, WebM or MP4 are far smaller and better quality at the same resolution.
What's the best format to convert photos to for the web?
WebP is the best choice for most web images — roughly 25–35% smaller than JPEG at the same visual quality, and fully supported by all modern browsers. Use JPEG when you need maximum compatibility with older software. Use PNG only when transparency is required, since it's lossless and photos saved as PNG will be much larger than JPEG or WebP. Avoid BMP and TIFF for web — they produce unnecessarily large files. See our JPEG vs WebP vs AVIF comparison for real file size data.
Can I convert PSD and AI files?
Yes — upload a PSD (Photoshop) or AI (Illustrator) file and convert it to JPEG, PNG, WebP, or any other image format. The converter flattens all layers and exports the final composite. This is useful for sharing designs or extracting images without needing the original Adobe software. Note that editable layer information is not preserved in the output — you get a flat image of whatever was visible in the file.
How do I extract audio from a video?
Upload your video file (MP4, MKV, MOV, etc.) and select MP3, M4A, or WAV as the output format. The converter strips the video track and exports just the audio. MP3 gives the widest compatibility, M4A (AAC) gives slightly better quality at the same file size, and WAV is uncompressed for the highest fidelity. This works for extracting a song, podcast, or voiceover from any video file.
Fix Corrupted Word, Excel & PowerPoint Files
Repair corrupted Word (.docx), Excel (.xlsx), and PowerPoint (.pptx) files online free. Upload your corrupted document and recover your content — no software, no signup.
Free online file repair tool — fix corrupted Word documents, repair corrupted Excel spreadsheets, recover damaged PowerPoint files and ODF documents. No data loss, no signup, instant download of the repaired file.
Frequently Asked Questions
What file formats can be repaired?
The repair tool supports all modern Microsoft Office formats — .docx, .xlsx, .pptx — as well as macro-enabled variants (.docm, .xlsm, .pptm) and legacy formats (.doc, .xls, .ppt). OpenDocument formats (.odt, .ods, .odp) used by LibreOffice and OpenOffice are also supported. If your file has one of these extensions and Word, Excel, or LibreOffice is refusing to open it, upload it here.
What causes Office files to get corrupted?
The most common cause is an interrupted save — the app crashed, the computer shut down, or a USB drive was disconnected mid-write. Because .docx, .xlsx, and .pptx files are ZIP archives containing XML files inside, any interruption during the write process can leave the archive incomplete or its internal directory broken. Other causes include storage drive errors, file transfer failures over a network, and software bugs that produce malformed XML when saving.
How much of my document will be recovered?
It depends on the type of corruption. Structural damage — broken ZIP index, incomplete archive, malformed XML — is usually fully recoverable with all text, tables, and formatting intact. Embedded images and charts are recovered when their data is still present in the file. If parts of the file were physically overwritten on disk (storage failure or ransomware), those sections cannot be recovered — but the repair tool will still extract everything that remains readable and give you back as much as possible.
Will formatting, images, and tables be preserved?
In most cases, yes. The repair process works on the file's internal structure without touching the content — so if the text, images, and formatting data are present in the file, they come through in the repaired output. The exception is severe corruption where whole sections of the file are missing or unreadable; in those cases the repair tool recovers whatever it can and the missing sections won't appear in the output.
Can corrupted password-protected files be repaired?
No — password-protected Office files are encrypted, so the repair tool cannot read or modify the contents without the password. Remove the password protection in Word or Excel before uploading, then run the repair. If the file is too corrupted to open for password removal, there is unfortunately no way to repair it without first decrypting it.
What should I do if the repair doesn't fully work?
Try Word's built-in Open and Repair first (File → Open → dropdown arrow next to Open → "Open and Repair"). If the file still won't open, rename a copy from .docx to .zip and try to extract word/document.xml using any ZIP program — your text will be inside <w:t> tags and is often readable even when the file itself won't load. Check cloud version history (OneDrive, Google Drive, Dropbox) for a clean earlier version, and look in %TEMP% for AutoRecover files ending in .asd. Our guide to fixing corrupted Word documents covers every method in detail.
Stable Diffusion & LoRA Training Image Prep
Resize and batch-export images for Stable Diffusion, LoRA, and Dreambooth training datasets. 512×512 or 1024×1024, with caption files. Free, no signup.
Free AI training image prep tool — resize photos to 1024×1024 or 512×512 for Stable Diffusion, LoRA, and Dreambooth datasets. Center crop or pad modes. Batch process an entire folder with ZIP download. No signup, instant PNG download.
Frequently Asked Questions
What output size should I use — 512×512 or 1024×1024?
Use 1024×1024 for modern models — SDXL, Flux, and most current LoRA and Dreambooth fine-tunes are trained and run at 1024px. Use 512×512 only if you are fine-tuning an older SD 1.5-based model, which was originally trained at that resolution. Training a 1.5-based model on 1024px images does not improve results and wastes VRAM. When in doubt, check the base model's documentation for its native resolution.
What's the difference between Center Crop and Pad modes?
Center Crop cuts the image to a square by removing equal amounts from the top and bottom (or left and right) without distorting proportions — the subject stays at full resolution but you lose the edges. Pad Black and Pad White add letterbox borders to make the image square without cropping anything — the full image is preserved but the borders become part of the training data. Center Crop is the right choice for most portraits and product shots. Pad modes are better when the full frame matters and edge content shouldn't be discarded.
How many images does a good LoRA or Dreambooth dataset need?
Quality matters more than quantity. For a subject LoRA (a specific person, object, or style), 15–30 high-quality, varied images typically outperform 100 similar or low-quality ones. Variation is key — different angles, lighting conditions, backgrounds, and expressions teach the model what is consistent about the subject versus what changes. Datasets with a lot of near-duplicate images (same angle, same lighting repeated) produce weaker, less flexible results. For a full guide covering resolution, captions, and common mistakes, see our Stable Diffusion & LoRA training guide.
Do I need caption files and what should they contain?
Captions are required for most modern fine-tuning workflows. Each image gets a matching .txt file with a short description of what is in that image. For subject LoRAs, a common format is a trigger word followed by descriptive tags — e.g. ohwx man, sitting, outdoor, casual clothing, sunlight. The trigger word is unique and rare (not a common English word) so the model learns to associate it specifically with your subject. Using the same caption for every image is fine for style LoRAs but produces weaker results for subject LoRAs where each image varies.
Does the tool change the image quality or format?
Images are output as PNG files at the chosen square resolution. PNG is lossless so no compression artifacts are introduced during the resize. The resizing uses high-quality resampling (Lanczos) which preserves sharpness better than nearest-neighbour or bilinear methods. Your source image quality is the ceiling — the tool does not enhance or upscale detail, it resizes and crops to the target dimensions as cleanly as possible.
How does batch mode work?
Select a folder from your computer and all supported image files inside it are processed at once with the same size, mode, and caption settings. The output is delivered as a single ZIP file containing all the resized PNGs and their matching caption .txt files — ready to be extracted directly into your training dataset folder. Batch mode processes entirely in your browser, so nothing is uploaded to a server and there is no file count limit.
Remove Background from Photo — No Photoshop Needed
Remove background from product photos, headshots, and signatures. Get a transparent PNG instantly — no Photoshop, no software, no signup.
Free AI background remover — remove background from image online instantly. Get a transparent PNG with no background. Supports JPG, PNG, WebP, BMP and more. No signup, no watermark, works on mobile and desktop.
Frequently Asked Questions
What image formats are supported?
You can upload JPG, PNG, WebP, BMP, TIFF, and JFIF files. The output is always a transparent PNG — this is the only format that supports a true alpha (transparency) channel that works across all browsers, design tools, and operating systems. If you need a different output format after removal, run the PNG through the Converter tab.
How does the AI background removal work?
The tool uses rembg, an open-source AI model based on U2-Net, which was trained on large datasets of images with labelled foregrounds and backgrounds. It analyses the image to identify subject boundaries and generates an alpha mask — a map of which pixels belong to the foreground versus the background. That mask is then applied to produce a transparent PNG. The whole process runs on our server and typically takes 2–5 seconds depending on image size.
Does it work on hair, fur, and fine edges?
Better than older non-AI methods, but not perfectly. The model handles hair and fur well when the subject contrasts clearly with the background — studio-style photos with a plain or blurred background give the best results. Loose, flyaway hair against a complex or similarly-coloured background is the hardest case for any AI removal tool. For critical edges on a professional result, use the output as a starting mask and refine it in Photoshop or GIMP.
What subjects does it work best on?
People, products, animals, and objects with clear boundaries all work well. Product photography on a plain background consistently gives clean results. Portraits and headshots with a blurred or plain background also work reliably. More complex cases — cluttered scenes, transparent objects like glasses, objects that blend into the background by colour — will give less precise results but still produce a usable starting point.
Is there a file size or resolution limit?
There is no hard file size cap for the background remover, but very large images (above 4000×4000 pixels) will take longer to process and the AI model will internally downscale them for analysis. For most practical uses — web images, product shots, profile photos — standard resolutions process quickly and return clean results. If your photo is very high resolution and edge quality is critical, consider downscaling to around 2000px on the longest side before uploading.
The output has jagged edges or leftover background patches — how do I fix it?
Jagged edges usually happen when the subject and background are a similar colour or when the photo has low contrast at the edges. Leftover patches typically come from busy backgrounds where the model couldn't reliably distinguish subject from surroundings. The fastest fix is to improve the source photo — shoot against a plain, contrasting background. For existing photos, the AI output gives you a rough mask that is much faster to clean up manually in a photo editor than starting from scratch.
Blog
Guides, tips, and comparisons for file compression, format conversion, image editing, and AI training datasets.