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Test scope & comparison notes
These are recorded facts, not a unified ranking. Tested tiers and scope are not consistently recorded. Read pricing with its date and timing with its conditions. Privacy observations reflect visible flows and statements, not a security audit.
Cross-task capability coverage across selected products
Each product is scored independently per task edge; switch tasks below while keeping shared products selected| Task edge | aconvert.com | CompressNow | Switch / compare |
|---|---|---|---|
| Image compression | 86/100 2048 × 2048 · PNG | 83/100 PNG · Output attached | Active task |
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Browse this task →| Criterion | Aconvert Image compression 86/100 Seven-aspect task score 100% free with no login, reducing the 4.14 MB anchor by 56.5% to 1.80 MB at PSNR 36.1 dB with full-resolution unwatermarked output. Tested export 2048 × 2048 · PNG Historical test · 2026-11-01 | CompressNow Image compression 83/100 Seven-aspect task score Free login-free on-device processing discloses format conversion upfront; size reduction is substantial, but PNG export is unavailable and transparency needs care. Tested export PNG · Output attached Historical test · 2026-10-18 |
|---|---|---|
| Pricing & rules | ||
| Pricing plans | Aconvert 100% free file conversion and compression service · 2026-11-01 Plan · source date Monthly / one-time Annual bill / period Quota & limits Free2026-11-01 ↗ Free Free Free 100% free without login, 40MB per file, up to 10 files per batch Full access to multi-format conversion and compression across documents, media, eBooks, and archives；40MB per-file limit, 10 files per batch, display ads present；Permanently free, no renewal；Perpetual access 1 plan / billing-period records, all listed; — means that period is not recorded. All conversion and compression features are 100% free with ad and voluntary donation support; 40MB per-file limit (up to 10 files per batch) with zero paid plans or paywalls. Cancellation, sources & verification recordCancellation and refund terms unverified Aconvert Official Homepage ↗ · 2026-11-01 Capture 1 ↗ Aconvert About and Free Model ↗ · 2026-11-01 Capture 1 ↗ | Compressnow online in-browser image compressor · 2026-10-21 Plan · source date Monthly / one-time Annual bill / period Quota & limits Compressnow Free Web2026-10-21 ↗ Free Free Free Free without login; up to 30 MB per image and up to 30 images at a time; individual or ZIP download. 1 plan / billing-period records, all listed; — means that period is not recorded. The official page and FAQ state that compression runs in the browser (images are not stored), supporting up to 30 MB per image and up to 30 images at a time for JPG/JPEG/PNG/GIF/WebP (output as JPG or WebP), with no paid tiers. Cancellation, sources & verification recordCompletely free web tool with no accounts or subscription charges. Compressnow official tool page and FAQ ↗ · 2026-10-21 Capture 1 ↗ |
| Free & trial allowance on the test date | Completely free, 40MB per file limit, up to 10 files per batch | 100% free, up to 30 MB per image and up to 30 images per batch |
| Cancellation & refunds | Not verified | Completely free web tool with no accounts or subscription charges. |
| Disclosure of costs & limits | Compression parameters and instructions clearly disclosed on page | Discloses upfront at the top of the page that output format is JPG or WebP ('Transparent areas turn white') |
| Task quality | ||
| Measured fixture results | File reduction: 56.5% · Output size: 1800.1 KB | File reduction: 85.99% · Output size: 579.8 KB |
| Fixture findings | Over 50% size reduction while preserving 2048px resolution and transparency; solid quality and easy to use. | Local compression reduced this fixture by about 86%; export changes to JPG or WebP, not PNG. |
| Original historical observation | Aconvert processes compression on cloud servers, reducing the 4.14 MB anchor by 56.5% to 1.80 MB under default Lossy 80 while maintaining SSIM 0.9966 and preserving micro-textures. | CompressNow is a fast, 100% client-side compressor: your image never leaves your browser, and in 0.9s it shrinks our 4.24 MB benchmark PNG to 579.8 KB (-85.99%, 7.14×) at 42.34 dB PSNR (02_workspace.png). Note that it only outputs JPG or WebP (disclosed upfront), so users with transparent PNGs should select the WebP toggle. |
| Suitable uses · historical assessment | Users and webmasters needing fast free image compression while preserving transparency and 2048px original resolution | Users who want to rapidly shrink bulky PNG screenshots or photos locally in-browser into high-quality JPG or WebP (-86% size) without uploading files to any server |
| Result & output evidence | ||
| Delivery capabilities | ||
| Recorded export specifications | 2048 × 2048 · PNG · No watermark in test | PNG · Output attached · No watermark in test |
| Historical specification note · not an official maximum | 2048 x 2048 (Full-resolution unwatermarked PNG) | 2048×2048 full-resolution free export (outputs as JPG or WebP; does not export native PNG) |
| Watermark observation | No watermark | Watermark-free |
| Batch & API | Supports up to 10 files concurrent upload with multi-format conversion | Supports up to 30 images (≤30 MB each) with one-click DOWNLOAD ZIP |
| Recorded free-tier dimensions | 2048 × 2048 | 2048 × 2048 |
| Attached file dimensions | 2048 × 2048 · PNG | Not verified |
| Speed & reliability | ||
| Timing observation | Network-observed server wait: 11.2s · End-to-end reference: 14.7s | Recorded local processing time: 0.9s · End-to-end reference: 0.9s |
| Date & fixture | 2026-11-01 · anchor_compress_v1 · US-West (California, AS2914) | 2026-10-18 · anchor_compress_v1 · US-West (California, AS2914) |
| Repeated tests & reliability | No standardized repetition count, success rate or variability range is recorded. | No standardized repetition count, success rate or variability range is recorded. |
| Interaction experience | ||
| Account requirements | No login in this test | No login in this test |
| Sign-in methods | All platform features accessible directly without registration or login | No registration or login required (100% local tool) |
| Manual adjustment | Not verified | Not verified |
| Interaction observations | Not verified | Clean single-page workspace with a live compression level slider (default 20%) and a single display ad banner, with zero popups or registration walls (02_workspace.png, 03_download.png). |
| Background & reputation | ||
| Service lifecycle notice | Not verified | Not verified |
| Operator | Aconvert Project (PDFConvertOnline.com) | CompressNow |
| Recorded origin | United States | France / European Independent Developer |
| Domain history record | Development team active since 2000 | 2012–Present (14-year online image compression tool) |
| Background & reputation assessment | Not verified | Classic multi-language online image weight reducer operating for over 10 years (currently V6.0). |
| External reputation record | Not verified | Not verified |
| Engineering & privacy | ||
| Processing location | Uploaded for cloud processing | On-device processing |
| Third-party tracking record | Google AdSense · Google Analytics | Not verified |
| Engineering & privacy assessment | Not verified | 100% local in-browser processing (`blob:https://compressnow.com/...`); FAQ explicitly states 'Compression runs in your browser: your images never leave your device.' |
| Retention statement | Claims deletion within 2 hours; deletion not independently verified | This flow runs locally; post-close deletion not independently verified |
| Evaluation basis | ||
| Pricing transparency | 31 / 35 100% free for up to 30 MB per image and 30 images at a time; transparently discloses next to the Format toggle: 'Format: JPG | WebP — Works everywhere. Transparent areas turn white.' (01_landing.png). | |
| Interaction restraint | 24 / 30 Clean single-page workspace with a live compression level slider (default 20%) and a single display ad banner, with zero popups or registration walls (02_workspace.png, 03_download.png). | |
| Background & reputation | 17 / 20 Classic multi-language online image weight reducer operating for over 10 years (currently V6.0). | |
| Engineering & privacy | 15 / 15 100% local in-browser processing (`blob:https://compressnow.com/...`); FAQ explicitly states 'Compression runs in your browser: your images never leave your device.' | |
| Task quality | 56 / 65 Size Reduction: -56.5% (4137.9 KB → 1800.1 KB, 2.3× ratio) · PSNR: 36.1 dB · SSIM: 0.9966 | 52.2 / 65 Shrinks file size by 85.99% (7.14×) at 42.34 dB PSNR and 0.9992 SSIM, though output format is converted to JPG or WebP (52.2/65) |
| Deliverable specifications | 20 / 20 Clean unwatermarked export (8/8); Export spec: 2048 x 2048 (Full-resolution unwatermarked PNG) | 15 / 20 Preserves full 2048×2048 dimensions and supports 30 MB files, but converts PNG inputs to JPG (or WebP) rather than native `.png` (15.0/20) |
| Processing speed | 8.5 / 15 Network-observed server wait: 11.2s (API mode: cloud_server; network upload 3.5s / end-to-end 14.7s shown for reference only, never penalized) | 14 / 15 100% local browser Canvas compression with 0 bytes uploaded in ~0.9s (14.0/15) |
