twilight venturesheap dump lens
JetBrains Marketplaceplugin 33908free viewer, Pro subscription
Heap Dump Lens opens the .hprof file a crashed or bloated JVM leaves behind, in the editor tab of IntelliJ IDEA and the other JetBrains IDEs. The class histogram comes up first, every class with its instance count and bytes, built by one streaming pass inside a fixed memory budget; in our own timing a 2.6 GB dump with twenty million objects indexed in about 12.5 seconds under a 512 MB cap. Thread dumps and GC logs in the unified -Xlog:gc* form open the same way, parsed, so the three files of one incident read in one place, with nothing separate to install. Pro computes the dominator tree over the whole object graph and ranks the top 500 retainers by the bytes each one would free.
- opens
- .hprof and .hprof.gz heap dumps and any file that starts with the hprof magic bytes; .tdump thread dumps, and jstack output through Tools | Open Thread Dump; unified GC logs through Tools | Open GC Log
- runs on
- every JetBrains IDE from 2024.2 on, Community editions included
- store
- JetBrains Marketplace, plugin 33908
- newest version
- 1.2.6, published 2026-09-09
- pro
- a subscription with its own 30-day trial; the price is quoted below as the store shows it
free
- Class histogram: every class in the dump with its instance count and shallow bytes, sortable and filterable, resolved to real class names
- Any size: one streaming pass with bounded memory; a 2.6 GB dump with twenty million objects indexes in seconds inside a 512 MB cap
- Compressed dumps: a .hprof.gz opens like a plain dump, inflated into a work directory with the progress shown, and the copy is removed when the tab closes
- Dump facts: object count, loaded classes, GC roots, format and id width, total heap bytes
- Thread dump viewer: .tdump files open parsed, threads with their state, daemon flag and stack frames, a state breakdown up top
- GC logs: unified -Xlog:gc* logs parsed into pause events with heap before and after, per-pause duration, max and total pause time
- Named errors: a file that is not an hprof dump reports a clear reason, never a stack trace
- Themes: eight looks for the histogram, the retained table, thread dumps and GC log pauses; trying one is free for the open window
pro
- Retained sizes: the dominator tree computed over the whole object graph, what each object would free if it were gone
- Top retainers: the ranked list of the heap's real owners, retained and shallow bytes side by side
- At scale: thirty million references extracted and dominators computed over twenty million objects in under half a minute on the same 2.6 GB dump
- Kept themes: a chosen look stays set from file to file
price, as the store shows it
Pro is $4.90 a month or $49 a year for individual use, $9.80 or $98 for organizations. Each Lens plugin comes with its own free 30-day Pro trial. Keep a subscription running for a year and JetBrains' perpetual fallback license kicks in: the version you had when that year started is yours for good, fixes included. Pro only ever adds features.
where it stops
- Viewer by design: it reads the dump, never rewrites it, and never attaches to a live process
- JFR recordings are out of scope: the files a JVM leaves behind, not flight recording
- No automated leak-suspect story: you get the dominator numbers and read them yourself
- Thread dump parsing covers HotSpot output, and a GC line the parser does not recognize stays out of the totals
what's new
- 1.2.6published 2026-09-09
Two new themes in the Theme picker, lamplighter and catacombs. They sit after the eight with a padlock and a hint until earned: lamplighter "unlocks when you share Lens with a colleague", catacombs "unlocks the first time Pro runs for you". Share Heap Dump Lens, new in the Help menu, shows a card with the marketplace page and your referral code; copying the card, or entering a code a colleague gave you, unlocks lamplighter. Catacombs comes with the first Pro run, a trial counts, and it stays after the trial ends. A theme earned this way is kept without Pro, here and in every Lens plugin. Picking a locked entry opens its unlock path instead of applying it. Thread dumps and GC logs read the saved theme under the same rule now.
- 1.2.5published 2026-09-08
Two fixes, one for a dump still indexing and one for a dump that could not be read. A class name typed into the filter while a large dump was still indexing was dropped when the histogram landed: the grid showed every class under a filled field until the next keystroke, and the rows now arrive already filtered. And a dump that could not be read no longer offers to compute retained sizes. That tab used to keep its button, and pressing it wrote "still indexing" into the header of a dump that had already failed; it now carries the reason the dump would not open.
- 1.2.4published 2026-09-07
A trial key that has run out no longer opens Pro. Trials from the JetBrains account arrive as signed keys, the same shape as a paid license, with the trial's last day inside; the signature alone was checked, and a signature holds for years, so retained sizes, the saved theme, the Supporter footer line and the thank-you meant for buyers all stayed on a lapsed trial while the trial-ended notice never showed. The last day inside the key decides now, and the day after it retained sizes ask for a license again, the tables open in the default look, the ended notice shows once, and the histogram, thread dumps and GC logs carry on free. Paid keys and the perpetual fallback license read as before.
more
Pricing, invoices and licensing questions go to [email protected]; anything else about the product to [email protected].