fio

At a glance

• Editor score
  8.8 / 10
• Pricing
  Free plan
• Best for
  Broad, rigorous cross-platform benchmarking
• Free plan
  Yes
• Paid from
  Free
• Random I/O tests
  Yes
• Founded
  2006
• Facts checked
  20 Sep 2026

• Where it wins

  • Covers sequential, random, mixed, IOPS, bandwidth, and latency workloads
  • Runs on Linux, Windows, macOS, and several Unix-like systems
  • Exports normal, terse, JSON, and JSON+ result formats

• Where it doesn't

  • Command-line and job-file workflows require technical familiarity
  • Results and workload behavior depend on configuration choices
  • Focused on engineering measurement rather than guided visual analysis

Our verdict on fio

fio is an open-source I/O tester for measuring storage and filesystem performance. It is intended for engineers and administrators who need configurable benchmarks across Linux, Windows, macOS, and several Unix-like operating systems. Workloads can cover sequential reads and writes, random operations, mixed sequential and random activity, and trims. Users define jobs through job files or command-line options, while results can include bandwidth, IOPS, submission latency, completion latency, total latency, CPU, and disk-utilization statistics where supported.

Pricing is straightforward: fio is available as free open-source software, with no paid plan structure described. That makes it suitable for teams that need broad benchmark coverage without a product subscription. Its standout strength is control over workload definition and output. Multiple I/O engines are available, including Linux native asynchronous I/O, and results can be produced in normal, terse, JSON, or JSON+ formats. This combination supports both direct command-line review and structured result handling in technical workflows.

The trade-off is that fio centers on configurable command-line and job-file execution rather than a guided benchmarking experience. That makes it a strong choice for technically experienced users who need repeatable, detailed measurements, but a less natural fit for users seeking a simple visual tool with an assisted setup flow. Choose fio when cross-platform coverage, workload depth, latency detail, IOPS measurement, and structured output matter most. Consider an alternative if your priority is a more guided interface rather than fine-grained benchmark configuration.

Your product? Our editors can test fio in depth and publish a review, labelled as paid · from $149/mo →

fio pricing

fio fact sheet

Alternatives to fio

• CrystalDiskMarkA configurable Windows disk benchmark with detailed speed, IOPS, and latency results.9.0
• HTHD Tune ProA capable Windows drive benchmark and diagnostic utility with a one-time license.8.5
• AJA System TestA free, video-focused benchmark for local, network, and AJA-connected storage workflows.8.4

See all fio alternatives →

fio vs the competition

• Ffio vs CrystalDiskMark
• FHTfio vs HD Tune Pro
• Ffio vs AJA System Test
• FDfio vs DiskSpd
• FMFfio vs Modern FS Benchmark
• FFfio vs Filebench

Compare fio with any tool side by side →

Featured on iTechGuides

fio is listed in our Disk Benchmark Software directory. Add the badge to your site — it links back to this page.

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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

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Last updated 7 Oct 2026 · How we research and update