diff --git a/api.go b/api.go
index da47cef83..e3f90852f 100644
--- a/api.go
+++ b/api.go
@@ -34,52 +34,53 @@ const interfaceBytes uint64 = 16
 
 // FileMatch contains all the matches within a file.
 type FileMatch struct {
-	// Ranking; the higher, the better.
-	Score float64 // TODO - hide this field?
-
-	// For debugging. Needs DebugScore set, but public so tests in
-	// other packages can print some diagnostics.
-	Debug string
-
 	FileName string
 
 	// Repository is the globally unique name of the repo of the
 	// match
 	Repository string
-	Branches   []string
+
+	// SubRepositoryName is the globally unique name of the repo,
+	// if it came from a subrepository
+	SubRepositoryName string
+
+	// SubRepositoryPath holds the prefix where the subrepository
+	// was mounted.
+	SubRepositoryPath string
+
+	// Commit SHA1 (hex) of the (sub)repo holding the file.
+	Version string
+
+	// Detected language of the result.
+	Language string
+
+	// For debugging. Needs DebugScore set, but public so tests in
+	// other packages can print some diagnostics.
+	Debug string
+
+	Branches []string
 
 	// One of LineMatches or ChunkMatches will be returned depending on whether
 	// the SearchOptions.ChunkMatches is set.
 	LineMatches  []LineMatch
 	ChunkMatches []ChunkMatch
 
-	// RepositoryID is a Sourcegraph extension. This is the ID of Repository in
-	// Sourcegraph.
-	RepositoryID uint32
-
-	// RepositoryPriority is a Sourcegraph extension. It is used by Sourcegraph to
-	// order results from different repositories relative to each other.
-	RepositoryPriority float64
-
 	// Only set if requested
 	Content []byte
 
 	// Checksum of the content.
 	Checksum []byte
 
-	// Detected language of the result.
-	Language string
-
-	// SubRepositoryName is the globally unique name of the repo,
-	// if it came from a subrepository
-	SubRepositoryName string
+	// Ranking; the higher, the better.
+	Score float64 // TODO - hide this field?
 
-	// SubRepositoryPath holds the prefix where the subrepository
-	// was mounted.
-	SubRepositoryPath string
+	// RepositoryPriority is a Sourcegraph extension. It is used by Sourcegraph to
+	// order results from different repositories relative to each other.
+	RepositoryPriority float64
 
-	// Commit SHA1 (hex) of the (sub)repo holding the file.
-	Version string
+	// RepositoryID is a Sourcegraph extension. This is the ID of Repository in
+	// Sourcegraph.
+	RepositoryID uint32
 }
 
 func (m *FileMatch) sizeBytes() (sz uint64) {
@@ -134,16 +135,10 @@ func (m *FileMatch) sizeBytes() (sz uint64) {
 // ChunkMatch is a set of non-overlapping matches within a contiguous range of
 // lines in the file.
 type ChunkMatch struct {
+	DebugScore string
+
 	// Content is a contiguous range of complete lines that fully contains Ranges.
 	Content []byte
-	// ContentStart is the location (inclusive) of the beginning of content
-	// relative to the beginning of the file. It will always be at the
-	// beginning of a line (Column will always be 1).
-	ContentStart Location
-
-	// FileName indicates whether this match is a match on the file name, in
-	// which case Content will contain the file name.
-	FileName bool
 
 	// Ranges is a set of matching ranges within this chunk. Each range is relative
 	// to the beginning of the file (not the beginning of Content).
@@ -153,8 +148,16 @@ type ChunkMatch struct {
 	// its length will equal that of Ranges. Any of its elements may be nil.
 	SymbolInfo []*Symbol
 
-	Score      float64
-	DebugScore string
+	// FileName indicates whether this match is a match on the file name, in
+	// which case Content will contain the file name.
+	FileName bool
+
+	// ContentStart is the location (inclusive) of the beginning of content
+	// relative to the beginning of the file. It will always be at the
+	// beginning of a line (Column will always be 1).
+	ContentStart Location
+
+	Score float64
 }
 
 func (cm *ChunkMatch) sizeBytes() (sz uint64) {
diff --git a/api_test.go b/api_test.go
index 8d26251d8..fe860d58c 100644
--- a/api_test.go
+++ b/api_test.go
@@ -17,6 +17,7 @@ package zoekt // import "github.com/sourcegraph/zoekt"
 import (
 	"bytes"
 	"encoding/gob"
+	"reflect"
 	"strings"
 	"testing"
 	"time"
@@ -136,3 +137,31 @@ func TestSizeBytesChunkMatches(t *testing.T) {
 		t.Fatalf("want %d, got %d", wantBytes, cm.sizeBytes())
 	}
 }
+
+func TestMatchSize(t *testing.T) {
+	cases := []struct {
+		v    any
+		size int
+	}{{
+		v:    FileMatch{},
+		size: 256,
+	}, {
+		v:    ChunkMatch{},
+		size: 112,
+	}, {
+		v:    candidateMatch{},
+		size: 72,
+	}, {
+		v:    candidateChunk{},
+		size: 40,
+	}}
+	for _, c := range cases {
+		got := reflect.TypeOf(c.v).Size()
+		if int(got) != c.size {
+			t.Errorf(`sizeof struct %T has changed from %d to %d.
+These are match structs that occur a lot in memory, so we optimize size.
+When changing, please ensure there isn't unnecessary padding via the
+tool fieldalignment then update this test.`, c.v, c.size, got)
+		}
+	}
+}
diff --git a/contentprovider.go b/contentprovider.go
index 68c41cfe1..89ddebbb5 100644
--- a/contentprovider.go
+++ b/contentprovider.go
@@ -369,11 +369,11 @@ func (p *contentProvider) fillContentChunkMatches(ms []*candidateMatch, numConte
 }
 
 type candidateChunk struct {
+	candidates []*candidateMatch
 	firstLine  uint32 // 1-based, inclusive
 	lastLine   uint32 // 1-based, inclusive
 	minOffset  uint32 // 0-based, inclusive
 	maxOffset  uint32 // 0-based, exclusive
-	candidates []*candidateMatch
 }
 
 // chunkCandidates groups a set of sorted, non-overlapping candidate matches by line number. Adjacent
@@ -566,8 +566,8 @@ func findSection(secs []DocumentSection, off, sz uint32) (int, bool) {
 
 func (p *contentProvider) chunkMatchScore(secs []DocumentSection, m *ChunkMatch, language string, debug bool) (float64, string) {
 	type debugScore struct {
-		score float64
 		what  string
+		score float64
 	}
 
 	score := &debugScore{}
@@ -654,8 +654,8 @@ func (p *contentProvider) chunkMatchScore(secs []DocumentSection, m *ChunkMatch,
 
 func (p *contentProvider) matchScore(secs []DocumentSection, m *LineMatch, language string, debug bool) (float64, string) {
 	type debugScore struct {
-		score float64
 		what  string
+		score float64
 	}
 
 	score := &debugScore{}
diff --git a/hititer.go b/hititer.go
index 89204e6d6..01a58d1e1 100644
--- a/hititer.go
+++ b/hititer.go
@@ -35,10 +35,10 @@ type hitIterator interface {
 
 // distanceHitIterator looks for hits at a fixed distance apart.
 type distanceHitIterator struct {
-	started  bool
-	distance uint32
 	i1       hitIterator
 	i2       hitIterator
+	distance uint32
+	started  bool
 }
 
 func (i *distanceHitIterator) String() string {
diff --git a/matchiter.go b/matchiter.go
index e7d3f39a2..68c6e4856 100644
--- a/matchiter.go
+++ b/matchiter.go
@@ -20,21 +20,25 @@ import (
 )
 
 // candidateMatch is a candidate match for a substring.
+//
+// Note: a lot of these can be in memory, so think about fieldalignment when
+// modify the fields of this structure.
 type candidateMatch struct {
-	caseSensitive bool
-	fileName      bool
-	symbol        bool
-	symbolIdx     uint32
-
 	substrBytes   []byte
 	substrLowered []byte
 
-	file uint32
+	file      uint32
+	symbolIdx uint32
 
 	// Offsets are relative to the start of the filename or file contents.
 	runeOffset  uint32
 	byteOffset  uint32
 	byteMatchSz uint32
+
+	// bools at end for struct field alignment
+	caseSensitive bool
+	fileName      bool
+	symbol        bool
 }
 
 // Matches content against the substring, and populates byteMatchSz on success