How much smaller will the WebP be compared to the source JPG?

WebP (RFC 9649 Zern, Massimino & Alakuijala, Google LLC, November 2024) is typically 25–35% smaller than JPEG at equivalent perceptual quality. The exact ratio depends on content: photographs with smooth gradients see the largest savings (35%+); images with sharp text or high-contrast edges see less (15–25%). The savings come from VP8's more efficient prediction modes and arithmetic coding (RFC 6386 Bankoski et al., November 2011) compared to JPEG's older Huffman-coded DCT (ITU-T T.81, September 1992). Re-encoding from JPEG cannot recover detail JPEG already discarded — the WebP encodes the existing pixels more compactly.

JPG to WebP Converter Online — Modern Compression for Smaller Files

Q: Does Safari support generating WebP from JPG?

No, not natively. Safari does not support image/webp output in HTMLCanvasElement.toBlob() as of 2026 — this is a limitation tracked in WebKit. Chrome supported native toBlob('image/webp') from version 18 (2012); Chromium-based Edge from version 79 (January 2020). Firefox added support in version 96 (January 2022); Firefox 98 added the quality parameter; Firefox 105 enabled lossless via quality=1.0. If the tool runs in Safari, conversion may use a JavaScript polyfill or fall back to a different format. For Safari users, the typical workaround is a JavaScript polyfill (libwebp compiled to WebAssembly) rather than an alternative format — Safari similarly lacks canvas.toBlob('image/avif') output.

Q: Will EXIF metadata transfer from JPG to WebP?

WebP supports an EXIF chunk per RFC 9649 §2.7.1.5 carrying the same EXIF 2.32 (JEITA CP-3451X / CIPA DC-X008-2019, revised 17 May 2019) metadata that JPEG stores in APP1 markers. However, browser Canvas-based conversions (the path this tool uses) typically strip EXIF as a side effect of the decode-to-pixels-then-re-encode flow — the metadata is read during JPG decode but not written into the output WebP. Privacy benefit when sharing photos online: GPS coordinates and camera fingerprints don't follow into the WebP. If preserving EXIF matters (archival, copyright), use a desktop tool like cwebp -metadata which writes EXIF to the WebP EXIF chunk explicitly.

Q: Should I use lossy or lossless WebP for converting JPG?

Lossy. JPEG sources are already lossy (JPEG quantisation is irreversible per ITU-T T.81 Annex K), so wrapping the decoded JPEG in lossless WebP would preserve every block artefact and ringing pattern at no quality benefit while being 2–3× the lossy WebP size. Lossy WebP at quality 80 typically produces files 25–30% smaller than the source JPG with no visible difference. Lossless WebP makes sense when the source is itself lossless (PNG, BMP, raw camera) — converting a lossy JPG losslessly bakes JPEG's compression artefacts into a much larger file with no fidelity gain.

Q: Will all my users' browsers display the WebP output?

Modern browsers yes. WebP display support: Chrome since version 32 (2014), Edge since 18 (2018), Firefox since 65 (January 2019), Safari since 14 (16 September 2020 / iOS 14), Opera since 19 (2014). Older browsers (IE 11, Safari 13 and earlier on iOS 13 and earlier) do not display WebP. For maximum compatibility on a website, use HTML with a WebP source and JPG fallback so older browsers fall through to the JPEG. RFC 9649 (November 2024) registers image/webp as a permanent IETF media type, formalising what was already universal.

JPG to WebP Converter — 25–35% Smaller Files via Modern Compression

WebP (RFC 9649 Zern, Massimino & Alakuijala, Google LLC, November 2024) is a modern image format built on VP8 video keyframes (RFC 6386 Bankoski et al., November 2011) for lossy mode and a custom LZ77 + Huffman/prefix-coding pipeline for lossless mode. It typically delivers 25–35% smaller files than JPEG (ITU-T T.81 / ISO/IEC 10918-1:1994, 18 September 1992) at equivalent perceptual quality, the result of more efficient prediction and entropy coding versus JPEG's older Huffman-coded DCT. The conversion runs locally via the WHATWG Canvas 2D Context + HTMLCanvasElement.toBlob('image/webp', quality) API. Browser support is asymmetric: Chrome 18+ (2012), Edge 79+ (Chromium-based, January 2020), Firefox 96+ (January 2022) (98+ for quality parameter, 105+ for lossless via quality=1.0), but Safari does NOT support image/webp output natively — Safari users hit a polyfill or alternative format. Re-encoding from JPG cannot recover detail JPEG already discarded; the WebP encodes the existing pixels more compactly.

How to convert JPG to WebP

Drop a .jpg file onto the tool or click to browse — single file or batch.
Pick a WebP quality level (1–100). 80–85 is the safe sweet spot — typically 25–35% smaller than the source JPG with no perceptible quality loss.
Watch the size comparison — WebP advantage is largest on smooth photographs (35%+) and smaller on flat-colour images (15–25%).
Download the WebP. Note: if you're on Safari, the conversion uses a JavaScript polyfill since Safari doesn't support native WebP encoding.

Common use cases

Migrating a legacy JPG image library to WebP for better Core Web Vitals (Largest Contentful Paint improves with smaller image payloads).
Shrinking product photos on a WebP-first e-commerce site, with HTML <picture> JPG fallback for Safari 13 / older browsers.
Producing WebP variants in a <picture> element fallback chain for image-heavy blog posts and landing pages.
Re-encoding a batch of camera-exported JPGs to WebP for cloud storage savings (typical 25–30% reduction at quality 80).

Frequently asked questions

How much smaller will the WebP be vs the source JPG?

WebP (RFC 9649, Nov 2024) typically 25–35% smaller than JPEG at equivalent perceptual quality. Photos with smooth gradients see 35%+; sharp-edge content sees 15–25%. Savings come from VP8 prediction (RFC 6386, Nov 2011) + boolean arithmetic entropy coder for lossy / Huffman for lossless vs JPEG's static Huffman DCT (T.81, Sept 1992). Re-encoding can't recover detail JPEG already discarded.

Does Safari support generating WebP from JPG?

Not natively. Safari does NOT support image/webp output in HTMLCanvasElement.toBlob() as of 2026 — a long-standing WebKit limitation. Chrome 18+ (2012), Edge 79+ Chromium (Jan 2020), Firefox 96+ (Jan 2022) all do natively. Safari users hit a JavaScript polyfill (libwebp compiled to WebAssembly is the typical choice).

Will EXIF metadata transfer from JPG to WebP?

WebP supports EXIF chunk per RFC 9649 §2.7.1.5 carrying same EXIF 2.32 (JEITA CP-3451X, May 2019) metadata as JPEG APP1. But Canvas-based conversions strip EXIF as a side effect of decode-to-pixels-then-re-encode. Privacy benefit when sharing. Use cwebp -metadata desktop tool to preserve EXIF explicitly.

Should I use lossy or lossless WebP for converting JPG?

Lossy. JPG sources are already lossy (T.81 Annex K quantisation is irreversible), so lossless WebP would preserve every JPEG block artefact at 2–3× the lossy WebP size with no fidelity gain. Lossy WebP at quality 80 = 25–30% smaller than source JPG, no visible difference. Lossless WebP makes sense from PNG/BMP/RAW sources only.

Will all my users' browsers display the WebP output?

Modern browsers yes: Chrome since 32 (2014), Edge ≥18 (2018), Firefox 65+ (Jan 2019), Safari 14+ (16 Sept 2020 / iOS 14), Opera 19+ (2014). Older browsers (IE 11, Safari 13 / iOS 13 and earlier) don't display WebP. Use HTML <picture> with WebP source + JPG fallback for max compatibility.

How WebP achieves 25–35% smaller — and Safari's output limitation

WebP's compression advantage stems from VP8's intra-prediction modes (4 modes for 16×16 luma macroblocks + 4 for 8×8 chroma + 10 modes for 4×4 luma sub-blocks per RFC 6386 §11–12) which predict pixel values from neighbouring blocks before encoding the residual, plus more efficient entropy coding (VP8's boolean arithmetic coder for lossy mode; Huffman/prefix coding for lossless mode) which packs entropy more efficiently than JPEG's static Huffman tables. For lossy WebP the pipeline mirrors VP8 keyframe encoding; for lossless (RFC 9649 §3) it uses LZ77 with a colour cache and four reversible transforms (predictor, colour, subtract-green, indexed colour) before final Huffman entropy coding. The result: a 1 MB JPEG photograph at quality 85 typically encodes as a 650–750 KB WebP at quality 80 with no perceptible loss. The conversion path here uses Canvas toBlob('image/webp') which, critically, is NOT supported in Safari as of 2026 — a WebKit limitation tracked at bugs.webkit.org. Chrome supported native WebP encoding from version 18 (2012); Edge ≥79 (Chromium-based, January 2020) inherits the same encoder; Firefox added it in version 96 (January 2022) with the quality parameter arriving in Firefox 98 and lossless via quality=1.0 in Firefox 105. Safari users converting JPG to WebP need either a polyfill (e.g., libwebp compiled to WebAssembly) or a desktop tool. For sites supporting Safari users, AVIF display works in Safari 16+ (Sept 2022) but Safari similarly does not support canvas.toBlob('image/avif') output — same WebKit limitation as image/webp output.

Source JPEG decoded per ITU-T T.81 / ISO/IEC 10918-1 baseline DCT
WebP output per RFC 9649 (lossy VP8 keyframes per RFC 6386 + lossless modes)
Adjustable WebP quality 1–100 (Firefox 98+ / Chromium since 2010)
Typical 25–35% file-size reduction at equivalent perceptual quality
Browser-native encoding in Chrome / Edge / Firefox 96+; Safari requires polyfill
Browser-side via WHATWG Canvas toBlob('image/webp', quality) — no upload, no server

Free. No signup. No file uploads. Ads via AdSense (consent required).

Sources (5)

ITU-T (CCITT) Study Group VIII & ISO/IEC JTC 1/SC 29/WG 10 (JPEG) (1992). Information technology — Digital compression and coding of continuous-tone still images: Requirements and guidelines. ITU-T Recommendation T.81 (18 September 1992) / ISO/IEC 10918-1:1994 — source JPEG baseline DCT bitstream.
Zern, J., Massimino, P., & Alakuijala, J. (Google LLC) (2024). WebP Image Format. RFC 9649, IETF (November 2024, Informational) — defines target WebP container; image/webp media type registration; lossy + lossless + animated modes.
Bankoski, J., Koleszar, J., Quillio, L., Salonen, J., Wilkins, P., & Xu, Y. (Google Inc.) (2011). VP8 Data Format and Decoding Guide. RFC 6386, IETF (November 2011, Informational) — VP8 keyframe bitstream used by WebP lossy mode.
JEITA / CIPA (2019). Exchangeable image file format for digital still cameras: Exif Version 2.32. JEITA CP-3451X / CIPA DC-X008-2019 (revised 17 May 2019 — JPEG APP1 EXIF; WebP container can carry EXIF in EXIF chunk per RFC 9649).
WHATWG (live). HTML Living Standard — Canvas 2D Context + HTMLCanvasElement.toBlob(). html.spec.whatwg.org/#2dcontext (browser conversion mechanism: decode JPG → toBlob('image/webp', quality); native WebP encoding in Chrome / Edge / Firefox 96+ since January 2022; Safari does NOT support image/webp output natively as of 2026).

These are the W3C, ISO/IEC, ITU-T, and IETF specifications the tool implements or builds on. Locate them on w3.org, iso.org, itu.int, or datatracker.ietf.org.

Related guides

WebP vs AVIF in 2026 — Which to Use and WhenWebP and AVIF are both worth shipping in 2026, but they solve different problems. Here's the practical comparison — compression, support, encode speed, fallbacks.