Are my images uploaded anywhere?

No, absolutely not. All image processing happens directly in your browser using WebAssembly technology. Your images never leave your device, are never uploaded to any server, and remain completely private. You can even use this tool offline after the initial page load.

Which image format should I choose?

WebP provides the best compression (30-50% smaller than JPEG) and is supported by all modern browsers. Choose JPEG for maximum compatibility with older devices. Use PNG for images with transparency or when you need lossless compression.

How much can I reduce image file size?

Typically 50-90% reduction is possible. Results depend on the original format and your settings. Converting a PNG to WebP with 80% quality often reduces file size by 80-90%. JPEG to WebP conversions typically achieve 30-50% reduction while maintaining similar quality.

What quality setting should I use?

For most images, 75-85% quality provides an excellent balance. For web use, 75-80% is often sufficient. For print or professional use, stick to 85-90%. Below 70%, quality degradation becomes more noticeable.

What does Strip Metadata do?

Metadata includes EXIF data like camera settings, GPS location, timestamps, and copyright information. Stripping metadata reduces file size slightly (usually 1-5%) and removes potentially sensitive information like where/when photos were taken.

Can I compress multiple images at once?

Currently, images are processed one at a time to ensure optimal performance and allow you to fine-tune settings for each image. You can quickly process multiple images by adjusting settings and repeating the compress-download cycle.

Does lossless mode work with all formats?

Lossless compression is available for WebP and PNG formats. With lossless mode, the image quality is preserved perfectly, but file size reduction is more modest (typically 20-40%) compared to lossy compression.

What's the best format for website images?

WebP is the best format for website images in 2026. It provides 30-50% better compression than JPEG/PNG and is supported by all major browsers. Use quality 75-80% for photos and lossless for graphics with text.

Can I resize images while compressing?

Yes! You can reduce the image dimensions using the resize slider. Reducing dimensions by 50% (e.g., from 4000px to 2000px) reduces file size by approximately 75%, in addition to quality-based compression.

How do I compress a PNG file without losing quality?

To compress a PNG file without quality loss, keep PNG as the output format and use the resize slider to reduce dimensions to your target display size. PNG is always lossless, so the main way to reduce file size is through resolution reduction and better compression algorithms. For the smallest possible file with some quality trade-off, convert to WebP with the lossless toggle enabled — WebP lossless is typically 20-30% smaller than PNG.

Is JPEG the same as JPG?

Yes, JPEG and JPG are the same image format. The .jpg extension originated from early Windows systems that required three-character file extensions, while .jpeg is the full name (Joint Photographic Experts Group). Localsquash outputs .jpeg files which are identical to .jpg and open in every image viewer and browser. If you need to convert jpeg to jpg, simply rename the file extension — no re-encoding is needed.

Which format gives the best compression for photos?

WebP at 75–80% quality is the best choice for photographs destined for the web or sharing apps. It produces smaller files than JPEG at the same perceived quality and is supported by all modern browsers and operating systems. For files that must be opened in older software (e.g., some print workflows), use JPEG at 80–85%.

What does stripping EXIF metadata actually remove?

EXIF data is a header embedded in JPEG and WebP files that stores camera model, lens, aperture, shutter speed, ISO, GPS coordinates, timestamp, and sometimes a preview thumbnail. Removing it reduces file size by 20–100 KB and prevents location data from being shared when you send the image to others. PNG files do not carry EXIF in the same way, so this option only meaningfully applies to JPEG and WebP output.

How does resizing interact with quality?

Resizing and quality are independent controls. Halving the resolution reduces pixel count by 75% and usually achieves a 70–80% file size reduction on its own. Lowering quality on top of that compounds the savings but also compounds any quality loss. For web thumbnails, resizing to the display pixel size and keeping quality at 80% is almost always better than keeping native resolution and dropping quality to 50%.

When should I use lossless mode?

Use lossless mode when the image contains text, thin lines, or diagrams where lossy compression introduces visible blurring or artefacts around sharp edges. This applies to screenshots, scanned documents, UI mockups, and medical images. Lossless WebP and PNG preserve every pixel exactly; the trade-off is that file sizes are larger than lossy output (typically 2–5× larger for photographs).

Is there a maximum file size I can compress?

There is no server-imposed limit. The practical constraint is your browser's memory — very large RAW files (50 MB and above) may be slow to process on devices with less than 4 GB of RAM. For typical camera JPEGs (3–10 MB) and phone photos (1–5 MB), compression completes in under a second on modern hardware.

Free Image Compressor & Converter

Compress JPEG, PNG, WebP up to 95% — no upload, runs entirely in your browser.

Drop an image or browse

JPEG, PNG, WebP & more

Files stay on your device

Settings

FormatWebP for best compression

Quality82 is a solid default

Higher = larger file. JPEG uses perceptual scaling.

Resize1.000 = original size

OptionsStrip EXIF / metadata

Lossless

Compression

Progress0%

TL;DR

Free browser-based image compressor using FFmpeg WebAssembly. Accepts JPEG, PNG, WebP, BMP, GIF. Outputs WebP, JPEG, or PNG. Quality range 1–100. Typical reduction: 50–90%. Includes crop, resize, metadata stripping. Files never leave your device. No account or watermark. Works offline.

What Is Browser-Based WebP, JPEG & PNG Image Compression?

Browser-based image compression uses FFmpeg compiled to WebAssembly to convert and compress images entirely inside your browser — no upload, no server, no queue. Drop in a JPEG, PNG, WebP, BMP, GIF, or RAW file and choose your output format: WebP for maximum compression (30-50% smaller than JPEG according to Google’s Web.dev benchmarks), JPEG for broad compatibility, or PNG for lossless results. You control the quality level (1–100), whether to strip EXIF metadata, and optionally resize or crop before encoding. The compressed image is written to memory and downloaded directly — your original file is never touched and never leaves your device.

What Do Format, Quality, and Resize Settings Mean?

Output Format: WebP uses a modern predictive coding algorithm that typically produces files 25–50% smaller than JPEG at equivalent visual quality, and supports both lossy and lossless modes. JPEG uses DCT-based lossy compression — universally supported but larger than WebP. PNG is lossless and ideal for screenshots, logos, or any image with transparency.
Quality Slider: Quality controls how aggressively the encoder discards imperceptible detail. For WebP and JPEG, 75–85% is the practical sweet spot — indistinguishable from the original for most photos. Dropping to 60–70% is fine for thumbnails and small previews. Below 50% introduces visible artefacts. PNG ignores this slider since it is always lossless.
Resize & Crop: Pixel count has a quadratic effect on file size — halving both width and height cuts the pixel count to one-quarter, which typically reduces file size by 70–80% at the same quality setting. The crop tool lets you remove empty borders or reframe to a specific aspect ratio before encoding, so the encoder never wastes bytes on unwanted pixels.

How to Compress an Image Online in Four Steps

Drop or select your file

Drag any image — JPEG, PNG, WebP, BMP, GIF — onto the upload area, or click to browse.

Resize or crop (optional)

Scale down with the resize slider or enter exact pixel dimensions. Use the crop overlay to trim borders or reframe to a standard aspect ratio. The live preview updates instantly as you adjust.

Choose output format and quality

Pick WebP for the smallest file, JPEG for maximum compatibility, or PNG for lossless output. Set quality to 75–85% for photos, or enable lossless mode for pixel-perfect preservation.

Compress and download

Click “Compress Image”. FFmpeg.wasm encodes the file locally and the result downloads automatically. The size reduction percentage is shown alongside the output file size.

Why Is WebP Smaller Than JPEG and PNG?

WebP is 25-50% smaller than JPEG at equivalent visual quality. Developed by Google as a successor to both JPEG and PNG, WebP’s lossy mode uses a block-based prediction algorithm derived from VP8 video compression, which models how the human visual system perceives contrast and colour. For a 3 MB JPEG photo, converting to WebP at 80% quality typically produces a file in the 1.2–1.8 MB range with no visible difference on screen.

WebP lossless mode uses a completely different algorithm (LZ77 + Huffman coding on prediction residuals) that beats PNG by 20–30% on typical photographs. However, for images with large areas of flat colour — like UI screenshots or logos — PNG often compresses more predictably, making it the safer choice when pixel-perfect reproduction is required. JPEG remains the best option when you need the output to open in software that does not yet support WebP.

Image Compression FAQ — Common Questions Answered

: No, absolutely not. All image processing happens directly in your browser using WebAssembly technology. Your images never leave your device, are never uploaded to any server, and remain completely private. You can even use this tool offline after the initial page load.
: WebP provides the best compression (30-50% smaller than JPEG) and is supported by all modern browsers. Choose JPEG for maximum compatibility with older devices. Use PNG for images with transparency or when you need lossless compression.
: Typically 50-90% reduction is possible. Results depend on the original format and your settings. Converting a PNG to WebP with 80% quality often reduces file size by 80-90%. JPEG to WebP conversions typically achieve 30-50% reduction while maintaining similar quality.
: For most images, 75-85% quality provides an excellent balance. For web use, 75-80% is often sufficient. For print or professional use, stick to 85-90%. Below 70%, quality degradation becomes more noticeable.
: Metadata includes EXIF data like camera settings, GPS location, timestamps, and copyright information. Stripping metadata reduces file size slightly (usually 1-5%) and removes potentially sensitive information like where/when photos were taken.
: Currently, images are processed one at a time to ensure optimal performance and allow you to fine-tune settings for each image. You can quickly process multiple images by adjusting settings and repeating the compress-download cycle.
: Lossless compression is available for WebP and PNG formats. With lossless mode, the image quality is preserved perfectly, but file size reduction is more modest (typically 20-40%) compared to lossy compression.
: WebP is the best format for website images in 2026. It provides 30-50% better compression than JPEG/PNG and is supported by all major browsers. Use quality 75-80% for photos and lossless for graphics with text.
: Yes! You can reduce the image dimensions using the resize slider. Reducing dimensions by 50% (e.g., from 4000px to 2000px) reduces file size by approximately 75%, in addition to quality-based compression.
: To compress a PNG file without quality loss, keep PNG as the output format and use the resize slider to reduce dimensions to your target display size. PNG is always lossless, so the main way to reduce file size is through resolution reduction and better compression algorithms. For the smallest possible file with some quality trade-off, convert to WebP with the lossless toggle enabled — WebP lossless is typically 20-30% smaller than PNG.
: Yes, JPEG and JPG are the same image format. The .jpg extension originated from early Windows systems that required three-character file extensions, while .jpeg is the full name (Joint Photographic Experts Group). Localsquash outputs .jpeg files which are identical to .jpg and open in every image viewer and browser. If you need to convert jpeg to jpg, simply rename the file extension — no re-encoding is needed.
: WebP at 75–80% quality is the best choice for photographs destined for the web or sharing apps. It produces smaller files than JPEG at the same perceived quality and is supported by all modern browsers and operating systems. For files that must be opened in older software (e.g., some print workflows), use JPEG at 80–85%.
: EXIF data is a header embedded in JPEG and WebP files that stores camera model, lens, aperture, shutter speed, ISO, GPS coordinates, timestamp, and sometimes a preview thumbnail. Removing it reduces file size by 20–100 KB and prevents location data from being shared when you send the image to others. PNG files do not carry EXIF in the same way, so this option only meaningfully applies to JPEG and WebP output.
: Resizing and quality are independent controls. Halving the resolution reduces pixel count by 75% and usually achieves a 70–80% file size reduction on its own. Lowering quality on top of that compounds the savings but also compounds any quality loss. For web thumbnails, resizing to the display pixel size and keeping quality at 80% is almost always better than keeping native resolution and dropping quality to 50%.
: Use lossless mode when the image contains text, thin lines, or diagrams where lossy compression introduces visible blurring or artefacts around sharp edges. This applies to screenshots, scanned documents, UI mockups, and medical images. Lossless WebP and PNG preserve every pixel exactly; the trade-off is that file sizes are larger than lossy output (typically 2–5× larger for photographs).
: There is no server-imposed limit. The practical constraint is your browser's memory — very large RAW files (50 MB and above) may be slow to process on devices with less than 4 GB of RAM. For typical camera JPEGs (3–10 MB) and phone photos (1–5 MB), compression completes in under a second on modern hardware.

How to Get the Smallest Image File Size

Resize to the display size before compressing

If an image will be displayed at 800×600 px on screen, saving it at 4000×3000 px and relying on the browser to downscale wastes 25× the bandwidth. Always resize to the largest size the image will actually be rendered at. This single step typically saves more than any quality setting adjustment.

Use WebP for web, JPEG for print and legacy software

WebP is the default for a reason — it is smaller and supported everywhere modern. However, some print bureaus, CMS platforms, and email clients still expect JPEG. When in doubt about the destination, generate both: WebP for web delivery and a JPEG fallback at 85% for everything else.

Strip metadata for sharing, keep it for archival

EXIF data is valuable for your personal photo library (camera settings, date, location) but unnecessary — and potentially privacy-exposing — when sharing publicly. Enable “Strip Metadata” for images going to social media or email, and disable it when archiving your originals.

Screenshots compress better as PNG than JPEG

Screenshots contain flat colour, sharp text edges, and repeating UI patterns that lossless PNG handles extremely well. Converting a screenshot to JPEG introduces blurring and ringing artefacts around text. If the screenshot has photographic content embedded in it, WebP lossless is a good middle ground.

How to Compress PNG Files Online

PNG files are lossless by design, which means they preserve every pixel but often result in large file sizes — especially for photographs. To compress a PNG file effectively, you have two approaches: keep PNG format and reduce dimensions (lossless, smaller pixel count = smaller file), or convert to WebP lossless for 20-30% smaller files at identical quality. Localsquash lets you compress PNG online using either method, entirely in your browser.

For screenshots, diagrams, and images with text, PNG remains the best format because its lossless compression avoids the blurring artefacts that JPEG introduces around sharp edges. For photographs stored as PNG, converting to WebP at 80-85% lossy quality typically reduces file size by 80-90% with no visible difference. The “Strip Metadata” option removes embedded colour profiles and other headers that add 10-50 KB to each file.

Convert JPEG to JPG — Are They the Same?

JPEG and JPG are the exact same format. The three-letter .jpg extension exists because early versions of Windows (DOS, Windows 3.1) required three-character file extensions, while macOS and Linux allowed .jpeg from the start. Modern operating systems treat both extensions identically — there is no quality, compression, or compatibility difference. To convert JPEG to JPG, you can simply rename the file extension. If you want to simultaneously compress the image, upload it to Localsquash, select JPEG output, and the downloaded file will be a fully optimised .jpeg that any system, browser, or app recognises.

Need to Compress Video Too?

Localsquash also includes a free online video compressor that uses the same browser-based FFmpeg engine. Compress MP4, MOV, AVI, MKV, and WebM files by up to 95% with H.264 encoding — no upload required. Trim, crop, adjust CRF and resolution, all without your footage leaving your device.

Compress a video

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