The best Kraken.io alternative takes 30 MB files on its free tool instead of 1 MB, holds an exact size like 100 KB in the tool and the API, converts iPhone HEIC for free, bills its API per image, and works with AI agents through an MCP server. Free, no signup.
✓30 MB files free
✓Exact size in the API
✓HEIC to JPG free
✓Billed per image
✓MCP server
By Sahadat Husain, who builds Blinkimg.·Kraken.io facts checked on its own pages on 2 October 2026.
Output format
– / –
Drop images or browse
JPEG · PNG · WEBP · AVIF · HEIC · up to 50 at once · max 30 MB each
HEIC
PNG
JPEG
AVIF
WEBP
Advanced settings1 on
SmallerAutoBetter
Auto tunes each image.
A hard cap for the number your form demands.
KB
A floor for forms that refuse small files.
Max resolution
×
Empty side keeps the ratio. Never enlarges.
Original · 9.8 MB
AVIF · 97.1 KB
−99%
A real result from the engine above: the same photograph, 9.8 MB in, 97.1 KB out as AVIF. Kraken's free tool would refuse it: the original is over 1 MB.
The short answer
Why Blinkimg is the best Kraken.io alternative
The Kraken.io image optimizer is a mature, developer-first service. Blinkimg answers the jobs it leaves open: big files for free, a size you set, agents that compress for you, and a price per image.
01Largest free file
30 MBKraken.io: 1 MB
Phone photos fit
Kraken's free web tool stops at 1 MB, which most phone photos pass. Blinkimg takes 30 MB free.
02Exact size
targetBytesKraken.io: None
Under 100 KB in one call
Kraken's API takes a quality from 1 to 100. Ours takes a byte target; our test JPEG landed at 99.7 KB under 100 KB.
03AI agents
MCP serverKraken.io: None
Compress from a sentence
Claude, ChatGPT, Cursor and VS Code use Blinkimg through its MCP server. Kraken states no agent integration.
04API billing
Per imageKraken.io: Per GB
A price you can predict
A credit compresses one image, whatever its size. Kraken bills the input data, with each started GB over quota charged.
05Free API
500 / moKraken.io: 100 MB
Every month, not once
Kraken gives a free account 100 MB of testing quota and does not say it renews. Ours resets every month.
06HEIC to JPG
FreeKraken.io: Paid
iPhone photos, no plan needed
Kraken's web tool converts only on paid plans. Our 1,956 KB HEIC became a 940.7 KB JPG on the free tool.
Kraken.io, fairly
What the Kraken.io image optimizer does well, and where it stops
Kraken.io has run since 2013 and shipped a new CLI this September. Its limits are about the free tool, the billing unit and what it leaves to you.
What Kraken.io does well
✓
Deep resizing
Eight resize strategies, gravity crops, a sharpening flag, and up to ten sizes from one upload.
✓
Broad input, PDF included
JPG, PNG, WebP, GIF, SVG, AVIF, HEIC and PDF in, animated WebP and GIF kept.
✓
Built for developers
Eight official SDKs, a CLI, callbacks, a sandbox, an OpenAPI spec, and direct pushes to S3, Azure and Google Cloud Storage.
✓
A mature WordPress plugin
Version 3.0.3, 10,000+ active installs, HEIC and AVIF, and one key for any number of sites.
✓
Cheap for small files in bulk
100,000 one-megabyte images cost $117 on its Enterprise plan, by its own price list.
Where Kraken.io stops
✕
1 MB and 20 files free
The free web tool refuses most phone photos, and a selection over 20 files as a whole.
✕
No target size
Quality 1 to 100 is the only lever; a 100 KB limit means guessing and checking.
✕
Billed by data
Plans sell input gigabytes; each started GB over quota is billed, and payments are non-refundable.
✕
Resize and convert are paid on the web
In the web tool both need a paid plan, as do URL and ZIP sources.
✕
No AI-agent route
No MCP server or agent integration on its site, docs or repositories.
Feature by feature
Kraken.io vs Blinkimg: every limit, side by side
Each Kraken.io cell is quoted from its pricing, web interface, docs, terms and repositories, read on 2 October 2026; each Blinkimg cell is a limit the tool or the API enforces. Green matches or beats the other side, amber has it with a condition, red lacks it, grey means Kraken states nothing.
Blinkimg
Kraken.io
Free tool
Largest file
30MB each
1MB each
Files at once
50a batch
20a batchmore refused as a whole
Resize and convert
✓Free
✓Paid plans
Formats
Opens
✓JPG, PNG, WebP, AVIF, HEIC
✓Also GIF, SVG, PDF
Saves as
✓JPG, PNG, WebP, AVIF
✓Also GIF
PDF compression
✕No
✓Yes, lossy levels
Control
Exact KB target
✓Yes, never over
✕Noquality 1 to 100
Resize
✓Width and heightnever enlarges
✓8 strategiesup to 10 sizes a call
Keep metadata
✓One switch
✓By groupgeotag, date, copyright
For developers
API billing
✓Per imageany size
✓Per input GBoverage per started GB
Free API each month
✓500 credits
✓100 MB testing quotarenewal not stated
SDKs and CLI
✓REST and OpenAPI
✓8 SDKs and a CLI
AI agents (MCP)
✓MCP server
✕None stated
WordPress plugin
✕Planned
✓10,000+ installs
Privacy
Files kept
✓Within 24 hoursdownload links one hour
✓API 1 hourfree web 12 hours
EXIF and GPS
✓Stripped by default
✓Stripped by default
Measured, not claimed
What our engine does with the files Kraken’s free tool refuses
Every figure is a file our engine produced. Kraken's free tool stops at 1 MB, so the camera-size files below would not reach it; compare the same small file on both if you like.
A 576.8 KB JPEG photo, 1920 × 1280
Original576.8 KB
JPG, Auto273.9 KB
AVIF123.9 KB
WebP218.9 KB
JPG under 50 KB48.7 KB
A 343 KB photo saved as HEIC
Original343 KB
JPG, Auto267.4 KB
AVIF121.9 KB
WebP211.4 KB
PNG997.2 KB
Auto is the setting the tool opens with. The JPG capped at 50 KB came back at 48.7 KB, −91.6% from the original, in one pass.
Reference file576.8 KBphoto.jpg
Target
Relative to source
Size
Saved
JPG under 100 KB
99.7 KB
−82.7%
JPG under 50 KB
48.7 KB
−91.6%
AVIF, AutoOur default
123.9 KB
−78.5%
JPG, AutoOur default
273.9 KB
−52.5%
Source: photo.jpg, 576.8 KB, 1920×1280, our reference photo, under byte targets, the API's targetBytes. One pass each, never over.
Tip 1
Send a target, not a quality
A byte target lands in one call. A quality setting needs a second call when the file comes out too big.
Tip 2
Write AVIF for the web
Our test photo measured 123.9 KB as AVIF against 273.9 KB as JPEG.
Tip 3
Know your average size
Kraken bills data and Blinkimg bills images, so your average file size decides which costs less.
Every byte count is the size of the actual file our engine produced from the named source, the same bytes you would download, not an estimate. The reference photo is one of our own photographs, an iguana on a branch, and the camera photo is a real one too. Drop your own file into the tool above to rerun any of them. How we measure names the sources and the settings.
The alternatives
Sites like Kraken.io: alternatives for developers and the web
The tools people use instead of Kraken.io, each described from its own website. Ours comes first.
01 · Best for exact sizes, agents and per-image pricing
BlinkimgOur pick
Blinkimg compresses and converts 50 images a batch at 30 MB each on the free tool, holds any byte target in the tool and the API, and runs in Claude, ChatGPT and Cursor through its MCP server. No signup.
ShortPixel is a WordPress-first optimizer with Lossy, Glossy and Lossless levels. Its online tool takes JPG, GIF and PNG up to 10 MB, more once you log in.
Runs
On its servers
Batch
Not stated
Largest file
10 MB signed out
Free plan
100 credits a month
✓A Glossy level between lossy and lossless
✓Generates WebP and AVIF copies
✓Compresses PDF files too
✕10 MB cap until you log in
✕No target size in KB
✕Its pages disagree on retention: 30 minutes or 2 hours
Squoosh is the open-source app from Google Chrome Labs. It compresses one image at a time in your browser, with a live before-and-after and codecs such as AVIF, MozJPEG, OxiPNG and JPEG XL.
ImageOptim is a free, open-source Mac app. It compresses without losing quality by default, strips EXIF and GPS, and handles JPEG, PNG, SVG and animated GIF.
Optimizilla, now at imagecompressor.com, compresses JPEG, PNG, WebP, GIF and SVG in your browser and lets you adjust each image before you save it. It states no daily limit.
XnConvert is a batch converter for Windows, Mac and Linux. It reads more than 500 formats, RAW and HEIC included, with over 80 operations and watch folders.
Pick by the files you send and how you send them. Three of the six picks are not ours.
An AI agent doing the work
BlinkimgOur pick
The MCP server lets Claude, ChatGPT or Cursor compress and convert local files.
A size limit in code
BlinkimgOur pick
Send targetBytes; the file comes back at or under it, in one call.
Phone photos, free
BlinkimgOur pick
30 MB a file on the free tool, HEIC converted, 50 at once.
PDFs and image sets
Kraken.io
PDF compression and up to ten sizes from one upload, through its API.
A WordPress site
ShortPixelorTinyPNG
Established WordPress plugins; Kraken has a good one too.
One image tuned by eye
Squoosh
A split view and every encoder option, in your browser.
Edge cases
The awkward cases, answered
What each side does with the jobs that trip optimizers up. Where Kraken.io states nothing, the card says so.
A 3 MB phone photo, free
Blinkimg
Accepted: up to 30 MB on the free tool.
Kraken.io
Refused by the free web tool: its limit is 1 MB.
Twenty-five files at once
Blinkimg
One batch of 25.
Kraken.io
The free tool refuses the whole selection; 20 is the most.
An upload form that wants 100 KB
Blinkimg
targetBytes: 100000. The file lands at or under it, in one call.
Kraken.io
No target; lower the quality and call again until it fits.
iPhone HEIC to JPG, free
Blinkimg
Converted on the free tool and the API.
Kraken.io
Conversion is paid in the web tool; the API converts.
A PDF to shrink
Blinkimg
Not offered. Blinkimg turns images into a PDF, not the other way.
Kraken.io
Compressed, always lossy, at screen, ebook, printer or prepress level.
Five sizes for a responsive site
Blinkimg
One job per size.
Kraken.io
Up to ten sizes from one upload.
An AI agent in Claude Code
Blinkimg
Connect the MCP server; the agent uploads and converts local files.
Kraken.io
No MCP server; an agent would have to wrap the API itself.
Keeping the GPS but not the camera data
Blinkimg
One switch: keep the metadata, or strip it.
Kraken.io
preserve_meta keeps chosen groups, geotag among them.
A month of 3 MB photos
Blinkimg
One credit an image, the same at 3 MB as at 300 KB.
Kraken.io
Billed by the gigabyte, so large photos cost more per image.
Privacy
Is it safe? How each side handles your images
Both services upload your images and delete them on a clock. The clocks and the paperwork differ.
Blinkimg
Deleted within 24 hours
Each image is processed on our servers and wiped within 24 hours. We keep nothing after that.
Metadata stripped by default
The GPS position and camera details stay out of the result unless you keep them.
No advertising cookies
Our analytics, Microsoft Clarity, sets no cookie, and the compressor is masked from it.
Never trained on, never sold
No image trains a model, ours or anyone else’s, and no person opens your files.
Kraken.io
API results for one hour
Its docs: optimized images stay on its servers for one hour only; its terms say API images are not stored.
Web downloads for 12 hours
The free web tool keeps results for 12 hours; paid web users can keep files in Cloud Storage.
A DPA and named sub-processors
A data processing agreement since 2023 names AWS, Stripe and others; the privacy policy dates from 2018.
A named operator
Nekkra UG in Berlin, with its register number in the imprint.
Both strip metadata by default and both are run by named companies; the difference is in the clocks and what each keeps for paid users.
For developers
Switching from the Kraken.io API, and what it costs
Both APIs take an image over HTTPS and return a smaller one. The calls map across; the bill depends on your file sizes.
Task
Blinkimg API
Kraken.io API
Compress
Upload, then create a job
POST the file or a URL
Quality
Auto, or a quality
lossy, or quality 1 to 100
Exact size
targetBytes, never over
Not offered
Convert
format on the job, 2 credits
convert: jpeg, png, gif, webp, avif
Resize
resize: width and height, never enlarges
8 strategies, up to 10 sizes
Keep metadata
stripMetadata: false keeps EXIF, XMP, IPTC
preserve_meta by group
AI agents
MCP server
None stated
Kraken's calls from its docs and OpenAPI reference, read on 2 October 2026. Ours from the job options in our OpenAPI document.
Images
Blinkimg pack
Kraken, 1 MB each
Kraken, 3 MB each
5,000
$15
$19 (Advanced)
$39 (Premium)
25,000
$59
$59 (Premium)
$93 (Enterprise)
100,000
$199
$117 (Enterprise)
$312 (Enterprise)
Kraken's cheapest plan for one month at its list prices on 2 October 2026, overage per started GB, 1 GB = 1,024 MB; the 1 MB and 3 MB averages are our assumptions. Ours: a credit pack, one credit an image, packs never expire.
The image API page has the endpoints and a curl example, and the MCP server page sets it up in Claude Code, Cursor or VS Code in a minute.
Switching
Switch from Kraken.io in one minute
No account to start. What the free web tool refused takes one drop.
01
Drop the same files
Up to 50 at once, 30 MB each, phone photos and HEIC included.
02
Pick a format or a size
Leave Auto on, pick WebP or AVIF, or type a Max file size like 100 KB for the whole batch.
03
Download and compare
Each row shows its real size and a before and after slider. Take one file, or all of them as a ZIP.
Compare
More comparisons
The same side-by-side treatment for the other tools people leave for Blinkimg.
Kraken.io's facts come from its own pages, docs and repositories; ours are the limits the tool and the API enforce and the files the engine produced.
Q:What is the best Kraken.io alternative?
For files over 1 MB on a free tool, an exact size, iPhone HEIC to JPG for free, or an AI agent through an MCP server, Blinkimg: 50 images at 30 MB each, and an API billed per image. For PDFs, ten sizes from one upload or a mature WordPress plugin, Kraken.io is strong.
Q:Is Kraken.io free?
Partly. Its free web tool takes 20 files of up to 1 MB, with resizing and conversion reserved for paid plans. A free account gets 100 MB of testing quota for the API; whether it renews is not stated. Blinkimg gives 500 free API credits every month.
Q:How much does Kraken.io cost?
Plans run from $5 a month for 500 MB of images to $79 for 60 GB, with each started GB over the quota billed from $5 down to $1. Yearly billing gives two months free, and its terms say payments are non-refundable. Every plan includes the API and the WordPress plugin.
Q:What is the Kraken.io file size limit?
1 MB a file on the free web tool, which most phone photos exceed, and 32 MB on paid plans and the API. More than 20 files at once are refused as a whole. Blinkimg's free tool takes 30 MB a file and 50 at once; Pro takes 90 MB.
Q:Can Kraken.io compress an image to a target size like 100 KB?
No. Its API takes a quality from 1 to 100 and has no target-size field, so you guess and check. Blinkimg's tool and API take a byte target and never return a file over it; our 576.8 KB test JPEG came back at 99.7 KB under 100 KB in one pass.
Q:Does Kraken.io work with AI agents or have an MCP server?
Not that it states: its site, docs, API reference, CLI and 15 public repositories mention no MCP server or agent integration. Blinkimg has an MCP server, so Claude, ChatGPT, Cursor and VS Code can compress, convert and upload local files through a sign-in or an API key.
Q:How long does Kraken.io keep my images?
API results stay on its servers for 1 hour; free web tool downloads last 12 hours; paid web users can keep files in Kraken's Cloud Storage. Its terms say it does not store images optimized by the API. Blinkimg deletes every file within 24 hours, and a download link lasts an hour.
Q:Can Kraken.io convert HEIC to JPG?
Its API accepts HEIC and can convert to JPEG, PNG, GIF, WebP or AVIF, but in the web tool conversion is a paid feature. Blinkimg converts HEIC to JPG, PNG, WebP or AVIF on the free tool; our iPhone test photo became a JPG in one drop.
Q:Is Kraken.io cheaper than Blinkimg?
For small files in bulk, yes: 100,000 images of 1 MB fit Kraken's Enterprise plan for $117 that month, against our $199 pack. For phone-size photos of 3 MB, Kraken's cost rises to $312, because it bills data, while our credit is one image whatever its size.
Q:Does Kraken.io remove EXIF and GPS data?
Yes, by default, in both modes, and it can keep chosen groups on request: the colour profile, date, copyright, geotag or orientation. Blinkimg strips EXIF and GPS by default too, applies the rotation first, and keeps the metadata when you tick Keep EXIF or set stripMetadata to false.
Q:Does Kraken.io have a WordPress plugin?
Yes, and it is a good one: version 3.0.3, more than 10,000 active installs, updated in June 2026 with HEIC, AVIF and PDF support, and one API key can serve any number of sites. Blinkimg’s WordPress plugin is planned; today its API and MCP server work from any code.
Q:Is Kraken.io still maintained?
Yes. It published an official command-line tool on 30 September 2026 and its WordPress plugin was updated in June 2026. Some public pages are older, such as a privacy policy last changed in 2018, but the product is active and run by Nekkra UG in Berlin.
Q:Which image optimizer is the best?
It depends on the job. For files under an exact size, iPhone photos or AI agents, Blinkimg. For PDFs, bulk small images on a budget or ten sizes from one upload, Kraken.io. For WordPress, ShortPixel, TinyPNG or Kraken. For one image tuned by eye, Squoosh.
Q:Why trust a Kraken.io comparison that Blinkimg wrote?
Because you can check each line. Every Kraken.io fact is quoted from its pricing, web interface, docs, terms and repositories, read on 2 October 2026, and linked below. The cost table uses its own price list. Where Kraken wins, on bulk price, PDF and resizing depth, the page says so.
